Noxious-insect repellent

ABSTRACT

Disclosed is a method of repelling noxious insects comprising the step of exposing said noxious insects to a composition containing from 0.1 to 90 wt. %, based on the total weight of the composition, of at least one of 2-(1-hydroxyalkyl)cycloalkanones represented by the following formula 11:  
                 
 
     wherein n is an integer of 3-10, R 1  is hydrogen or a straight-chain saturated hydrocarbon radical having 1-6 carbon atoms; R 2  is hydrogen or methyl group and R m ′ represents m′ of the same or different, straight-chain or branched, saturated or unsaturated, hydrocarbon radicals R which, as a substituent group, can be bonded to carbocyclic atoms; m′ is an integer of 0-8, provided that m′ should be at least 2 when n is at least 4 and both the R 1  and R 2  are alkyl groups; the sum of the carbon atoms of R m ′ does not exceed 12; and, further, when n is 4, R may be an isopropylidene group which intramolecularly bridges between the third and sixth carbocyclic atoms.

TECHNICAL FIELD

[0001] The present invention relates to noxious-insect repellentscomprising a compound which is substantially odorless and has anextremely excellent noxious-insect repelling effect and durability.

BACKGROUND ART

[0002] As a noxious-insect repellent for protecting bodies fromnoxious-insects such as mosquitoes, flies and the like, a preparationapplied to the skin which contains N,N-diethyltoluamide has so far beenextensively used. Additionally, it has been known thatp-menthane-3,8-diol and 8-hydroxy-p-menthan-3-one have a stronginsect-repelling effect (Japanese Patent Application Kokai Nos.60-199,804 and 5-173,104) and that 2-ethyl-1,3-hexanediol and2-(1-hydroxyethyl)-cyclohexanol also have a similar repelling effect(U.S. Pat. No. 2,407,205). However, problems have been posed such thatN,N-diethyltoluamide has a peculiar offensive odor andp-menthane-3,8-diol, 8-hydroxy-p-menthan-3-one, 2-ethyl-1,3-hexanediolor 2-(1-hydroxyethyl)-cyclohexanol lacks durability. Therefore,development of novel noxious-insect repellents has been expected.

[0003] The present invention has been accomplished under thesecircumstances. The object of the present invention is to providenoxious-insect repellents which have no peculiar offensive odor andexhibit an excellent noxious-insect repelling effect and durability.

DISCLOSURE OF INVENTION

[0004] We, the inventors, as a result of assiduous studies conducted inorder to achieve the above object, have succeeded in synthesizingsubstantially odorless compounds having an excellent noxious-insectrepelling effect and durability, and thus accomplished the presentinvention.

[0005] Namely, the first embodiment of the present invention is anoxious-insect repellent which contains 0.1-90% by weight, based on thetotal weight, of at least one of 2-(1-hydroxy-alkyl)-cycloalkanolsrepresented by the following general structural formula (1):

[0006] wherein n is an integer of 3-10, R¹ is hydrogen or astraight-chain saturated hydrocarbon radical having 1-6 carbon atoms; R²is hydrogen or methyl group; R_(m) represents m of the same ordifferent, straight-chain or branched, saturated or unsaturated,hydrocarbon radicals R which, as a substituent group, can be bonded tocarbocyclic atoms; m is an integer of 0-8, provided that m should be atleast 1 when either one of R¹ or R² is an alkyl group and m should be atleast 2 when both the R¹ and R² are alkyl groups; the sum of the carbonatoms of R_(m) does not exceed 8; and, further, when n is 4, R may by anisopropylidene group which intramolecularly bridges between the thirdand sixth carbocyclic atoms.

[0007] Among the above 2-(1-hydroxyalkyl)-cycloalkanols, preferred are2-(1-hydroxyisopropyl)-5-methyl-cyclohexanol derivatives represented bythe following general structural formula (2):

[0008] wherein R³ is a straight-chain or branched, saturated orunsaturated, hydrocarbon radical having 1-8 carbon atoms;2-(1-hydroxyisopropyl)-5,6-dimethyl-cyclohexanol represented by thefollowing chemical structural formula (3):

[0009] 2-(1-hydroxyisopropyl)-5-methyl-6-methylene-cyclohexanolrepresented by the following chemical structural formula (4):

[0010] and, 2-(1-hydroxyalkyl)-cycloalkanols represented by thefollowing general structural formula (5):

[0011] wherein n, m, R_(m) and R¹ are the same as above; particularly,2-(hydroxymethyl)-cycloalkanols represented by the following generalstructural formula (6):

[0012] wherein n, m and R_(m) are the same as above; and inter alia2-(hydroxymethyl)-3-methyl-6-isopropyl-cyclohexanol represented by thefollowing chemical structural formula (7):

[0013] Furthermore, among the 2-(1-hydroxyalkyl)-cycloalkanolsrepresented by the general structural formula (5), particularlypreferred are 2-(1-hydroxymethyl)-cyclohexanol derivatives representedby the following general structural formula (8):

[0014] wherein R⁴ is a straight-chain or branched, saturated orunsaturated, hydrocarbon radical having 1-8 carbon atoms; and2-(1-hydroxymethyl)-cyclopentanol derivatives represented by thefollowing general structural formula (9):

[0015] wherein R⁴ is the same as above.

[0016] Furthermore, preferred examples of the present invention include3-(1-hydroxyalkyl)-borneol derivatives represented by the followinggeneral structural formula (10) which, in the2-(1-hydroxyalkyl)-cycloalkanols represented by the general structuralformula (1), is specified by defining n as 4 to form a 6-memberedcarbocycle and R_(m) as an isopropylidene group intramolecularlybridging between the third and sixth carbocyclic atoms:

[0017] wherein R⁵ and R⁶ are hydrogens or lower alkyl groups having atmost 3 carbon atoms and the sum of the carbon atoms of R⁵ and R⁶ is 0-3.

[0018] The most preferable noxious-insect repellents of the above firstembodiment of the present invention contain 0.1-90%, preferably 3-20%,by weight, based on the total weight, of at least one compound selectedfrom the group consisting of the 2-(1-hydroxyalkyl)-cycloalkanolsrepresented by the formulae (2), (3), (4), (5), (6), (7), (8), (9) and(10).

[0019] The second embodiment of the present invention is anoxious-insect repellent which contains 0.1-90% by weight, based on thetotal weight, of at least one of 2-(1-hydroxyalkyl)-cycloalkanonesrepresented by the following general structural formula (11):

[0020] wherein n, R¹ and R² are the same as above; R_(m)′ represents m′of the same or different, straight-chain or branched, saturated orunsaturated, hydrocarbon radicals R which, as a substituent group, canbe bonded to carbocyclic atoms; m′ is an integer of 0-8, provided thatm′ should be at least 2 when n is at least 4 and both the R¹ and R² arealkyl groups; the sum of the carbon atoms of R_(m)′ does not exceed 12;and, further, when n is 4, R may be an isopropylidine group whichintramolecularly bridges between the third and sixth carbocyclic atoms.

[0021] Among the above compounds represented by the formula (11) thatare contained in the noxious-insect repellents, preferably used are2-(1-hydroxyisopropyl)-cycloalkanone derivatives represented by thefollowing general structural formula (12):

[0022] wherein n′ is an integer of 3 or 4; when n′ is 3, m′ is at least1; and when n′ is 4, m′ is at least 2.

[0023] Among the 2-(1-hydroxyisopropyl)-cycloalkanone derivativesrepresented by the above formula (12), further particularly preferred is2-(1-hydroxyisopropyl)-5-methyl-cyclopentanone represented by thefollowing chemical formula (13) and2-(1-hydroxyisopropyl)-5-methyl-cyclohexanone derivatives represented bythe following chemical formula (14):

[0024] wherein R³ is the same as above.

[0025] Among the 2-(1-hydroxyalkyl)-cycloalkanones represented by theabove general structural formula (11), further preferred are2-(1-hydroxyalkyl)-cycloalkanones represented by the following generalstructural formula (15) and 2-(hydroxymethyl)-cycloalkanones representedby the following general structural formula (16), particularly,2-(1-hydroxymethyl)-3-methyl-6-isopropyl-cyclohexanone represented bythe following chemical structural formula (17):

[0026] wherein n, m′, R_(m)′ and R¹ are the same as above;

[0027] wherein n, m′ and R_(m)′ are the same as above; and

[0028] The preferred examples of the present invention include3-(1-hydroxyalkyl)-camphor derivatives represented by the followinggeneral structural formula (18) which, in the2-(1-hydroxyalkyl)-cycloalkanones represented by the foregoing generalformula (11), is specified by defining n as 4 to form a 6-memberedcarbocycle and R_(m)′ as an isopropylidene group intramolecularlybridging between the third and sixth carbocyclic atoms:

[0029] wherein R⁵ and R⁶ are the same as above.

[0030] The most preferred second embodiment of the present invention arenoxious-insect repellents containing 0.1-90%, preferably 3-20%, byweight, based on the total weight, of at least one compound selectedfrom the group consisting of the compounds represented by the abovechemical structural formulae (12), (13), (14), (15), (16), (17) and(18).

[0031] The construction of the present invention will be explained indetail hereinafter.

[0032] The 2-(1-hydroxyisopropyl)-5,6-dimethyl-cyclohexanol shown by thechemical structural formula (3) which falls in the scope of the abovegeneral structural formulae (1) and (2), that is,p-menthane-2-methyl-3,8-diol (referred to as “MMD” hereinafter), can beobtained by admixing 2,3,7-trimethyl-6-octenal (referred to as “TO”hereinafter) with an aqueous solution of an acid, such as sulfuric acidor the like, while stirring. Alternatively, the2-(1-hydroxyisopropyl)-5-methyl-6-methylene-cyclohexanol shown by thechemical structural formula (4), that is,p-menthane-2-methylene-3,8-diol (referred to as “MMED” hereinafter), canbe obtained by admixing 3,7-dimethyl-2-methylene-6-octenal (referred toas “DMO” hereinafter) with an aqueous solution of an acid such assulfuric acid or the like, while stirring.

[0033] It has been known that both the 2,3,7-trimethyl-6-octenal (TO)and 3,7-dimethyl-2-methylene-6-octenal (DMO) are compounds which caneasily be obtained from citronellal (U.S. Pat. No. 3,463,818). Both theMMD and MMED obtained by the above synthesizing process are colorless,transparent, oily substances having substantially no odor.

[0034] The 2-(1-hydroxyisopropyl)-5-methyl-cyclohexanol derivativesshown by the general structural formula (2), which are used in thepresent invention, i.e., p-menthane-2-alkyl-3,8-diol derivatives, can beobtained by admixing 2-alkyl-3,7-dimethyl-6-octenal with an aqueoussolution of an acid such as sulfuric acid or the like, while stirring.It has been known that the 2-alkyl-3,7-dimethyl-6-octenal, which is astarting material for producing the p-menthane-2-alkyl-3,8-diol, caneasily be obtained from citronellal (Summary Report of Lectures,presented in 35th Symposium on Perfume, Terpene & Essential OilChemistry, p. 62, 1991).

[0035] The p-menthane-2-alkyl-3,8-diol derivatives obtained by the abovesynthesizing process are colorless, transparent, oily substances havingsubstantially no odor.

[0036] The above p-menthane-2-alkyl-3,8-diol derivatives include, forexample:

[0037] p-menthane-2-ethyl-3,8-diol,

[0038] p-menthane-2-propyl-3,8-diol,

[0039] p-menthane-2-butyl-3,8-diol,

[0040] p-menthane-2-pentyl-3,8-diol,

[0041] p-menthane-2-hexyl-3,8-diol,

[0042] p-menthane-2-isopropyl-3,8-diol,

[0043] p-menthane-2-(3-methylbutyl)-3,8-diol,

[0044] p-menthane-2-(2-propenyl)-3,8-diol,

[0045] p-menthane-2-(3-butenyl)-3,8-diol,

[0046] p-menthane-2-(cis-3-hexenyl)-3,8-diol,

[0047] p-menthane-2-octyl-3,8-diol,

[0048] and the like.

[0049] The 2-hydroxymethyl-2-alkyl-cyclohexanols shown by the generalformula (8) falling in the scope of the 2-(1-hydroxyalkyl)-cycloalkanolderivatives shown by the above general structural formula (1), which areapplied in the present invention, can be produced by a manufacturingprocess wherein 2-ethoxycarbonyl cyclohexanone obtained fromcyclohexanone by a conventional process is reacted with an alkylbromideto provide 2-ethoxycarbonyl-2-alkyl-cyclohexanone which is then reducedby using lithium borohydride as a reducing agent (Organic Synthesis,Vol. 47, p. 20, 1967).

[0050] The 2-hydroxymethyl-cyclohexanol derivatives obtained by theabove synthesizing process are colorless, transparent, oily substanceshaving substantially no odor.

[0051] The 2-hydroxymethyl-cyclohexanol derivatives to be employed inthe present invention include compounds derived by adding a saturatedstraight-chain or branched alkyl group having 1-12 carbon atoms to thesecond carbocyclic atom of a 2-hydroxymethyl-cyclohexanol, such as:

[0052] 2-hydroxymethyl-2-methyl-cyclohexanol,

[0053] 2-hydroxymethyl-2-ethyl-cyclohexanol,

[0054] 2-hydroxymethyl-2-propyl-cyclohexanol,

[0055] 2-hydroxymethyl-2-isopropyl-cyclohexanol,

[0056] 2-hydroxymethyl-2-butyl-cyclohexanol,

[0057] 2-hydroxymethyl-2-hexyl-cyclohexanol,

[0058] 2-hydroxymethyl-2-octyl-cyclohexanol,

[0059] 2-hydroxymethyl-2-decyl-cyclohexanol,

[0060] 2-hydroxymethyl-2-dodecyl-cyclohexanol,

[0061] and the like.

[0062] The substituent alkyl group at the second carbon atom ispreferred to have about 1-8 carbon atoms in view of the volatility ofthe compounds.

[0063] The 2-hydroxymethyl-2-alkyl-cyclopentanols shown by the generalformula (9) falling in the scope of the 2-(1-hydroxyalkyl)-cyclopentanolderivatives shown by the above general structural formula (1), which areapplied in the present invention, can be produced by a manufacturingprocess wherein 2-ethoxycarbonyl-cyclopentanone obtained fromcyclopentanone by a conventional process is reacted with an alkylbromideto provide 2-ethoxycarbonyl-2-alkyl-cyclopentanone which is then reducedby using lithium borohydride as a reducing agent (Organic Synthesis,Vol. 47, p. 20, 1967).

[0064] It has been reported that 2-hydroxy-2-nonyl-cyclopentanol, as anintermediate of synthesis, was isolated by the above process. However,there has never been disclosed that this compound has a noxious-insectrepelling effect (Chem. Pharm. Bull., p. 3047, Vol. 29, 1981).

[0065] The 2-hydroxymethyl-cyclopentanol derivatives obtained by theabove synthesizing process are colorless, transparent, oily substanceshaving substantially no odor.

[0066] The 2-hydroxymethyl-cyclopentanol derivatives of the formula (9)to be employed in the present invention include compounds derived byadding a saturated straight-chain or branched alkyl group having 1-12carbon atoms to the second carbocyclic atom of a2-hydroxymethyl-cyclopentanol, such as:

[0067] 2-hydroxymethyl-2-methyl-cyclopentanol,

[0068] 2-hydroxymethyl-2-ethyl-cyclopentanol,

[0069] 2-hydroxymethyl-2-propyl-cyclopentanol,

[0070] 2-hydroxymethyl-2-isopropyl-cyclopentanol,

[0071] 2-hydroxymethyl-2-butyl-cyclopentanol,

[0072] 2-hydroxymethyl-2-hexyl-cyclopentanol,

[0073] 2-hydroxymethyl-2-octyl-cyclopentanol,

[0074] 2-hydroxymethyl-2-decyl-cyclopentanol,

[0075] 2-hydroxymethyl-2-dodecyl-cyclopentanol,

[0076] and the like.

[0077] The substituent alkyl group at the second carbocyclic atom ispreferred to have about 1-8 carbon atoms in view of the volatility ofthe compounds.

[0078] The 2-hydroxymethyl-3-methyl-6-isopropyl-cyclohexanol, that is,2-hydroxymethyl-menthol (referred to as “HMMO” hereinafter) shown by thechemical formula (7), which is applied in the present invention, can beproduced by a manufacturing process wherein 2-ethoxycarbonyl-menthone isobtained from menthone and diethyl carbonate, and then reduced.

[0079] The HMMO obtained by the above synthesizing process is acolorless, transparent, oily substance having substantially no odor.

[0080] The 2-hydroxymethyl-cycloalkanol derivatives shown by the generalstructural formula (6), which are employed in the present invention, canbe produced by reducing, with lithium borohydride, a 2-ethoxycarbonylcycloalkanone which has been obtained by a conventional process from acycloalkanone comprising a straight-chain or branched, saturated,substituent hydrocarbon radical having 0-8 total carbon atoms added to acarbocyclic atom thereof (Organic Synthesis, Vol. 47, p. 20, 1967).

[0081] The 2-hydroxymethyl-cycloalkanol derivatives obtained by theabove synthesizing process is a colorless, transparent, oily substancehaving substantially no odor.

[0082] The 2-hydroxymethyl-cycloalkanol derivatives of the formula (6),which are employed in the present invention, include2-hydroxymethyl-cycloalkanols comprising a 5-12-membered carbocycle andsuch compounds further comprising at least one saturated, straight-chainor branched alkyl substituent group having 1-8 total carbon atoms addedto the carbocyclic atoms thereof, such as:

[0083] 2-hydroxymethyl-3-methyl-cyclopentanol,

[0084] 2-hydroxymethyl-3-ethyl-cyclopentanol,

[0085] 2-hydroxymethyl-4-propyl-cyclopentanol,

[0086] 2-hydroxymethyl-4-isopropyl-cyclopentanol,

[0087] 2-hydroxymethyl-4-methyl-cyclohexanol,

[0088] 2-hydroxymethyl-5-methyl-cyclohexanol,

[0089] 2-hydroxymethyl-6-methyl-cyclohexanol,

[0090] 2-hydroxymethyl-4-ethyl-cyclohexanol,

[0091] 2-hydroxymethyl-4-(t-butyl)-cyclohexanol,

[0092] 2-hydroxymethyl-6-(t-butyl)-cyclohexanol,

[0093] 2-hydroxymethyl-6-(sec-butyl)-cyclohexanol,

[0094] 2-hydroxymethyl-4-(t-amyl)-cyclohexanol,

[0095] 2-hydroxymethyl-3,4-dimethyl-cyclohexanol,

[0096] 2-hydroxymethyl-4,5-dimethyl-cyclohexanol,

[0097] 2-hydroxymethyl-3,3,5-trimethyl-cyclohexanol,

[0098] 2-hydroxymethyl-3,5,5-trimethyl-cyclohexanol,

[0099] 2-hydroxymethyl-cycloheptanol,

[0100] 2-hydroxymethyl-cyclooctanol,

[0101] 2-hydroxymethyl-2-ethyl-cyclooctanol,

[0102] 2-hydroxymethyl-cyclododecanol,

[0103] and the like.

[0104] The manufacturing process of the 2-(1-hydroxyalkyl)-cycloalkanolderivatives to be employed in the present invention is not specificallylimited. The 2-(1-hydroxyalkyl)-cycloalkanol derivatives can be producedby reducing, with a reducing agent such as lithium borohydride, a2-(1-hydroxyalkyl)-cycloalkanone derivative which has been obtained by aconventional process from an aldehyde and a 2-bromocycloalkanonederivative comprising a straight-chain or branched, saturatedsubstituent hydrocarbon radical having 0-8 total carbon atoms added tothe carbocyclic atom thereof (J. Amer. Chem. Soc., Vol. 89, p. 5727,1967).

[0105] The above 2-(1-hydroxyalkyl)-cycloalkanol derivatives include2-(1-hydroxyalkyl)-cycloalkanols comprising a 5-12-membered carbocycleand these compounds further comprising at least one saturated,straight-chain or branched alkyl substituent group having 0-8 totalcarbon atoms added to the carbocyclic atoms thereof, such as:

[0106] 2-(1-hydroxyethyl)-3-methyl-cyclopentanol,

[0107] 2-(1-hydroxybutyl)-3-ethyl-cyclopentanol,

[0108] 2-(1-hydroxyethyl)-4-propyl-cyclopentanol,

[0109] 2-(1-hydroxypropyl)-4-ethyl-cyclopentanol,

[0110] 2-(1-hydroxyethyl)-4-methyl-cyclohexanol,

[0111] 2-(1-hydroxyamyl)-5-methyl-cyclohexanol,

[0112] 2-(1-hydroxyethyl)-5-methyl-cyclohexanol,

[0113] 2-(1-hydroxybutyl)-4-ethyl-cyclohexanol,

[0114] 2-(1-hydroxyethyl)-3-methyl-cyclohexanol,

[0115] 2-(1-hydroxybutyl)-6-methyl-cyclohexanol,

[0116] 2-(1-hydroxyethyl)-3-methyl-6-isopropyl-cyclohexanol,

[0117] 2-(1-hydroxybutyl)-4-isopropyl-cyclohexanol,

[0118] 2-(1-hydroxyethyl)-3,4-dimethyl-cyclohexanol,

[0119] 2-(1-hydroxyethyl)-4,5-dimethyl-cyclohexanol,

[0120] 2-(1-hydroxybutyl)-cycloheptanol,

[0121] 2-(1-hydroxyethyl)-cyclooctanol,

[0122] 2-(1-hydroxybutyl)-cyclooctanol,

[0123] 2-(1-hydroxyethyl)-cyclodecanol,

[0124] and the like.

[0125] The 3-(1-hydroxyalkyl)-borneol derivatives shown by the generalformula (10), to be employed in the present invention, can be regardedas a specific structure which, in the2-(1-hydroxyisoalkyl)-6-methyl-hexanol falling in the scope of thegeneral formula (1), is specified by defining n as 4 and the third andsixth carbocyclic atoms thereof are intramolecularly bridged with anisopropylidene group. These are known compounds. These compounds can beproduced by reducing, with a reducing agent such as lithium aluminumhydride, sodium borohydride or the like, 3-(1-hydroxyalkyl)-camphorderivatives which can be prepared according to the process disclosed inJ. Org. Chem. Vol. 56, p. 378-387 (1991).

[0126] The 3-(1-hydroxyalkyl)-borneol derivatives to be employed in thepresent invention include:

[0127] 3-(1-hydroxymethyl)-borneol,

[0128] 3-(1-hydroxyethyl)-borneol,

[0129] 3-(1-hydroxypropyl)-borneol,

[0130] 3-(1-hydroxy-1-methylethyl)-borneol,

[0131] 3-(1-hydroxybutyl)-borneol,

[0132] 3-(1-hydroxy-1-methylpropyl)-borneol, and

[0133] 3-(1-hydroxy-2-methylpropyl)-borneol.

[0134] These compounds are substantially odorless.

[0135] Among the 2-(1-hydroxyisopropyl)-cycloalkanone derivatives of thegeneral structural formula (12) which fall in the scope of the abovegeneral structural formula (11), the2-(1-hydroxyisopropyl)-5-methyl-cyclopentanone shown by the chemicalformula (13) can be produced by oxidizing2-(1-hydroxyisopropyl)-5-methyl-cyclopentanol, which can be preparedaccording to the process disclosed in Japanese Patent Application KokaiNo. 3-250,533, with a salt or oxide of a metal, such as chromium,manganese, silver or the like, or an organic oxidizing agent (dimethylsulfoxide or the like). The thus obtained2-(1-hydroxyisopropyl)-5-methyl-cyclopentanone is a substantiallyodorless, pale yellow, oily substance.

[0136] Similarly, the 8-hydroxy-p-menthan-3-one derivatives shown by thegeneral formula (14) which fall in the scope of the chemical formula(12) can be produced by oxidizing, with a salt or oxide of a metal, suchas chromium, manganese, silver or the like, a metal oxide thereof or anorganic oxidizing agent (dimethyl sulfoxide or the like), a diol whichcan be prepared by admixing a 3,7-dimethyl-6-octenal derivative having asubstituent hydrocarbon radical at the second carbon atom thereof withan aqueous solution of an acid such as sulfuric acid or the like, whilestirring. The thus obtained 8-hydroxy-p-menthan-3-one derivatives aresubstantially odorless, colorless and transparent, oily substances.

[0137] The above 8-hydroxy-p-menthan-3-one derivatives include:

[0138] 8-hydroxy-2-methyl-p-menthan-3-one,

[0139] 8-hydroxy-2-methylene-p-menthan-3-one,

[0140] 8-hydroxy-2-ethyl-p-menthan-3-one,

[0141] 8-hydroxy-2-propyl-p-menthan-3-one,

[0142] 8-hydroxy-2-isopropyl-p-menthan-3-one,

[0143] 8-hydroxy-2-butyl-p-menthan-3-one,

[0144] 8-hydroxy-2-isobutyl-p-menthan-3-one,

[0145] 8-hydroxy-2-hexyl-p-menthan-3-one,

[0146] 8-hydroxy-2-(2-ethylhexyl)-p-menthan-3-one,

[0147] 8-hydroxy-2-(2-propenyl)-p-menthan-3-one,

[0148] 8-hydroxy-2-(3-pentenyl)-p-menthan-3-one,

[0149] 8-hydroxy-2-(2-propenyl)-p-menthan-3-one,

[0150] and the like.

[0151] The manufacturing process of the 2-hydroxymethyl-cycloalkanonederivatives shown in the general structural formula (16) which areemployed in the present invention is not specifically limited. The2-hydroxymethyl-cycloalkanone derivatives can be produced by reducingselectively an ethoxycarbonyl group of a 2-ethoxycarbonyl cycloalkanonederivative which has been obtained by a conventional process from acycloalkanone comprising a straight-chain or branched, saturatedsubstituent hydrocarbon radical having 0-12 total carbon atoms added toa carbocyclic atom thereof (Chem. Pharm. Bull., Vol. 29, No. 10, p.3047, 1981).

[0152] The 2-hydroxymethyl-cycloalkanone derivatives of the generalstructural formula (16) include 2-hydroxymethyl-cycloalkanone comprisinga 5-12-membered carbocycle and such compounds further comprising atleast one saturated, straight-chain or branched, substituent hydrocarbonradical having 0-12 total carbon atoms added to the carbocyclic atomthereof, such as:

[0153] 2-hydroxymethyl-3-methyl-cyclopentanone,

[0154] 2-hydroxymethyl-3-ethyl-cyclopentanone,

[0155] 2-hydroxymethyl-4-propyl-cyclopentanone,

[0156] 2-hydroxymethyl-4-isopropyl-cyclopentanone,

[0157] 2-hydroxymethyl-4-methyl-cyclohexanone,

[0158] 2-hydroxymethyl-5-methyl-cyclohexanone,

[0159] 2-hydroxymethyl-6-methyl-cyclohexanone,

[0160] 2-hydroxymethyl-4-ethyl-cyclohexanone,

[0161] 2-hydroxymethyl-4-(t-butyl)-cyclohexanone,

[0162] 2-hydroxymethyl-6-(t-butyl)-cyclohexanone,

[0163] 2-hydroxymethyl-6-(sec-butyl)-cyclohexanone,

[0164] 2-hydroxymethyl-4-amyl-cyclohexanone,

[0165] 2-hydroxymethyl-3,4-dimethyl-cyclohexanone,

[0166] 2-hydroxymethyl-4,5-dimethyl-cyclohexanone,

[0167] 2-hydroxymethyl-cycloheptanone,

[0168] 2-hydroxymethyl-cyclooctanone,

[0169] 2-hydroxymethyl-2-ethyl-cyclooctanone,

[0170] 2-hydroxymethyl-cyclododecanone,

[0171] and the like.

[0172] These compounds are substantially odorless.

[0173] The 2-(hydroxymethyl)-3-methyl-6-isopropyl-cyclohexanone shown inthe chemical formula (17) which is employed in the present invention,that is, 2-hydroxymethyl-menthone (referred to as “HMMT” hereinafter),can be manufactured by heating, while stirring, menthone andformaldehyde in methanol in the presence of potassium carbonate.

[0174] According to the above synthesizing process, the HMMT that is asubstantially odorless and colorless, transparent, oily substance isproduced.

[0175] The manufacturing process of the 2-(1-hydroxyalkyl)cycloalkanonederivatives shown by the general structural formula (15) which areemployed in the present invention, is not specifically limited. The2-(1-hydroxyalkyl)-cycloalkanone derivatives can be produced accordingto a conventional process from a 2-bromocycloalkanone derivative havinga straight-chain or branched, saturated substituent hydrocarbon radicalcomprising 0-12 total carbon atoms added to a carbocyclic atom thereofand an aldehyde (J. Amer. Chem. Soc., Vol. 89, p. 5727, 1967).

[0176] The 2-(1-hydroxyalkyl)-cycloalkanone derivatives include2-(1-hydroxyalkyl)-cycloalkanones comprising a 5-12-membered carbocycleand such compounds further comprising at least one saturated,straight-chain or branched, substituent hydrocarbon radical of 0-12total carbon atoms added to the carbocyclic atom(s) thereof, such as:

[0177] 2-(1-hydroxyethyl)-3-methyl-cyclopentanone,

[0178] 2-(1-hydroxybutyl)-3-ethyl-cyclopentanone,

[0179] 2-(1-hydroxyhexyl)-4-propyl-cyclopentanone,

[0180] 2-(1-hydroxypropyl)-4-ethyl-cyclopentanone,

[0181] 2-(1-hydroxyamyl)-4-methyl-cyclohexanone,

[0182] 2-(1-hydroxyethyl)-3,5-dimethyl-cyclohexanone,

[0183] 2-(1-hydroxyethyl)-6-methyl-cyclohexanone,

[0184] 2-(1-hydroxybutyl)-1-ethyl-cyclohexanone,

[0185] 2-(1-hydroxyethyl)-3-methyl-cyclohexanone.

[0186] 2-(1-hydroxybutyl)-6-methyl-cyclohexanone,

[0187] 2-(1-hydroxyethyl)-3-methyl-6-isopropyl-cyclohexanone,

[0188] 2-(1-hydroxybutyl)-4-isopropyl-cyclohexanone,

[0189] 2-(1-hydroxyethyl)-3,4-dimethyl-cyclohexanone,

[0190] 2-(1-hydroxyethyl)-4,5-dimethyl-cyclohexanone,

[0191] 2-(1-hydroxybutyl)-cycloheltanone,

[0192] 2-(1-hydroxyethyl)-cyclooctanone,

[0193] 2-(1-hydroxybutyl)-cyclooctanone,

[0194] 2-(1-hydroxyethyl)-cyclodecanone,

[0195] and the like.

[0196] These compounds are substantially odorless.

[0197] The 3-(1-hydroxyalkyl)-camphor derivatives of the generalstructural formula (18), which are employed in the present invention,can be regarded as a specific structure which, in the2-(1-hydroxy-isoalkyl)-6-methyl-hexanone shown by the general structuralformula (13), is specified by defining n as 4 and the third and sixthcarbocyclic atoms thereof are intramolecularly bridged with anisopropylidene group. These are known compounds. These compounds can bemanufactured according to the process disclosed in J. Org. Chem., Vol.56, p. 378-387 (1991). However, the manufacturing process is notspecifically limited.

[0198] Such 3-(1-hydroxyalkyl)-camphor derivatives include:

[0199] 3-(1-hydroxymethyl)-camphor,

[0200] 3-(1-hydroxyethyl)-camphor,

[0201] 3-(1-hydroxypropyl)-camphor,

[0202] 3-(1-hydroxy-1-methyethyl)-camphor,

[0203] 3-(1-hydroxybutyl)-camphor,

[0204] 3-(1-hydroxy-1-methylpropyl)-camphor, and

[0205] 3-(1-hydroxy-2-methylpropyl)-camphor.

[0206] These compounds are substantially odorless.

[0207] There are several stereoisomers to be applied to the presentinvention. However, when they are used as a noxious-insect repellent,they can be in either a singular stereoisomeric form or a mixture. Fromthese compounds, cis and trans forms can be isolated by a columntreatment or the like and separated as crystals. All of these isomershave an excellent repelling effect against noxious-insects such asmosquitoes.

[0208] These compounds to be used in the present invention are allsubstantially odorless.

[0209] Noxious-insect repellent compositions in various dosage forms canbe prepared by blending the above-described compound as an activeingredient with a base of cosmetics or pharmaceuticals which are usuallyapplied to human bodies or animals. They can be formulated in, forexample, lotions, aerosols, milky lotions, creams or the like. Thesecompounds can be further incorporated with other noxious-insectrepellents, antioxidants, UV-absorbers, humectants or other additives.

[0210] The above compounds or the above prepared compositions of thepresent invention can be applied directly to human bodies or animals.Besides, substrates, such as sheets, films, nets or the like, which havepreliminarily been treated with the above compound or composition bymeans of application, impregnation or blending, can also be used.

[0211] The quantity of the above compounds to be formulated in thenoxious-insect repellents depends upon the dosage form, usage or otherconditions. However, it is preferred to be generally 0.1-90%, morepreferably 3-20%, by weight. The noxious-insect repellents according tothe present invention are used effectively against noxious-insects, suchas mosquitoes such as tiger mosquitoes, Aedes albopictus; black flies;ticks; millipedes; armyworms; slugs; and the like.

BEST MODE FOR CARRYING OUT THE INVENTION

[0212] The present invention will be explained hereinafter morespecifically by way of synthesizing examples of the compounds applied inthe present invention and working examples. In the examples, the percentis by weight unless otherwise specified.

SYNTHESIZING EXAMPLE 1 Synthesis of p-menthane-2-methyl-3,8-diol

[0213] 50 g of TO was gradually added to 300 g of a 20% sulfuric acidaqueous solution and then the mixture was vigorously agitated for 20hours. Extraction was conducted with 150 ml diethylether from thisreaction solution. The diethylether layer was washed twice with 100 mlof a 10% sodium carbonate aqueous solution and then further washed twicewith 100 ml of saturated brine.

[0214] This diethylether layer was dried with anhydrous sodium sulfate,and then the diethylether was removed to provide a crude reactionproduct. This crude reaction product was purified by means of silica gelcolumn chromatography (eluent: hexane/ethylacetate=4/1) and 43 g of acolorless, transparent, oily substance was obtained (yield: 74.5%).

[0215] In the mass spectrometric measurement of the obtained oilysubstance, a peak corresponding to the loss of water from the parent ionpeak was observed. In the elemental analysis, measured values ofC=70.87% and H=11.93% were found (theoretical values of C and H:C=70.92% and H=11.90%). Besides, in the measurement of the infraredabsorption spectrum, strong absorptions by a hydroxyl group at 3,400cm⁻¹ and 1,180 cm⁻¹ were observed. Furthermore, absorptions by a cyclicstructure at 1,480 cm⁻¹ and 920 cm⁻¹˜940 cm⁻¹ were observed. As aresult, the production of the MMD was ascertained.

SYNTHESIZING EXAMPLE 2 Synthesis of p-menthane-2-methylene-3,8-diol

[0216] 50 g of DMO was gradually added to 300 g of a 20% sulfuric acidaqueous solution and then the mixture was vigorously agitated for 20hours. Extraction was conducted with 150 ml diethylether from thisreaction solution. The diethylether layer was washed twice with 100 mlof a 10% sodium carbonate aqueous solution and then further washed twicewith 100 ml of saturated brine.

[0217] This diethylether layer was dried with anhydrous sodium sulfate,and then the diethylether was removed to provide a crude reactionproduct. This crude reaction product was purified by means of silica gelcolumn chromatography (eluent: hexane/ethylacetate=4/1) and 43 g of acolorless, transparent, oily substance was obtained (yield: 74.5%). Inthe mass spectrometric measurement of the obtained oily substance, apeak corresponding to the loss of water from the parent ion peak wasobserved. In the elemental analysis, measured values of C=71.72% andH=10.88% were found (theoretical values of C and H: C=71.69% andH=10.94%). Besides, in the measurement of the infrared absorptionspectrum, strong absorptions by a hydroxyl group at 3,400 cm⁻¹ and 1,180cm⁻¹ were observed. Furthermore, absorptions by a cyclic structure at1,480 cm⁻¹ and 920 cm⁻¹˜940 cm⁻¹ were observed. As a result, theproduction of the MMED was ascertained.

SYNTHESIZING EXAMPLE 3 Synthesis of p-menthane-2-ethyl-3,8-diol

[0218] 50 g of 2-ethyl-3,7-dimethyl-6-octenal was gradually added to 300g of a 20% sulfuric acid aqueous solution and then the mixture wasvigorously agitated for 20 hours. Extraction was conducted with 150 mldiethylether from this reaction solution. The diethylether layer waswashed twice with 100 ml of a 10% sodium carbonate aqueous solution andthen further washed twice with 100 ml of saturated brine. Thisdiethylether layer was dried with anhydrous sodium sulfate, and then thediethylether was removed to provide a crude reaction product. This crudereaction product was purified by means of silica gel columnchromatography (eluent: hexane/ethylacetate=4/1) and 42 g of a paleyellow, oily substance was obtained (yield: 77.3%). In the massspectrometric measurement of the obtained oily substance, a peakcorresponding to the loss of water from the parent ion peak wasobserved. In the elemental analysis, measured values of C=71.77% andH=12.21% were found (theoretical values of C and H: C=71.95% andH=12.08%). Thus, the production of p-menthane-2-ethyl-3,8-diol wasascertained.

SYNTHESIZING EXAMPLE 4 Synthesis of p-menthane-2-(2-propenyl)-3,8-diol

[0219] 50 g of 2-(2-propenyl)-3,7-dimethyl-6-octenal was gradually addedto 300 g of a 20% sulfuric acid aqueous solution and then the mixturewas vigorously agitated for 20 hours. Extraction was conducted with 150ml diethylether from this reaction solution. The diethylether layer waswashed twice with 100 ml of a 10% sodium carbonate aqueous solution andthen further washed twice with 100 ml of saturated brine. Thisdiethylether layer was dried with anhydrous sodium sulfate, and then thediethylether was removed to provide a crude reaction product. This crudereaction product was purified by means of silica gel columnchromatography (eluent: hexane/ethylacetate=4/1) and 41 g of a paleyellow, oily substance was obtained (yield: 76.6%). In the massspectrometric measurement of the obtained oily substance, a peakcorresponding to the loss of water from the parent ion peak wasobserved. In the elemental analysis, measured values of C=73.51% andH=12.04% were found (theoretical values of C and H: C=73.54% andH=11.93%). Thus, the production of p-menthane-2-(2-propenyl)-3,8-diolwas ascertained.

SYNTHESIZING EXAMPLE 5 Synthesis of p-menthane-2-hexyl-3,8-diol

[0220] 50 g of 2-hexyl-3,7-dimethyl-6-octenal was gradually added to 300g of a 20% sulfuric acid aqueous solution and then the mixture wasvigorously agitated for 20 hours. Extraction was conducted with 150 mldiethylether from this reaction solution. The diethylether layer waswashed twice with 100 ml of a 10% sodium carbonate aqueous solution andthen further washed twice with 100 ml of saturated brine. Thisdiethylether layer was dried with anhydrous sodium sulfate, and then thediethylether was removed to provide a crude reaction product. This crudereaction product was purified by means of silica gel columnchromatography (eluent: hexane/ethylacetate=4/1) and 38 g of a paleyellow, oily substance was obtained (yield: 71.1%). In the massspectrometric measurement of the obtained oily substance, a peakcorresponding to the loss of water from the parent ion peak wasobserved. In the elemental analysis, measured values of C=75.10% andH=12.33% were found (theoretical values of C and H: C=74.94% andH=12.58%). Thus, the production of p-menthane-2-hexyl-3,8-diol wasascertained.

SYNTHESIZING EXAMPLE 6 Synthesis of 2-hydroxymethyl-2-octyl-cyclohexanol

[0221] 20 g of 2-ethoxycarbonyl-cyclohexanone was dissolved in 15 mldimethylformamide and stirred. Then, a solution comprising 200 mldimethylformamide with 6 g sodium hydride dispersed therein wasgradually added dropwise to the above 2-ethoxycarbonyl-cyclohexanonesolution. After the addition of the sodium hydride solution had beencompleted, the reaction solution was stirred for 2 hours at roomtemperature under a nitrogen gas stream. A solution comprising 15 mldimethylformamide with 25 g octyl bromide dissolved therein was furtheradded dropwise to the reaction solution. After the addition had beencompleted, the temperature was raised to 100° C. and agitation wasconducted for 2 hours. The reaction solution was cooled down, thenpoured into iced water and extraction with 100 ml diethylether wasconducted twice. The diethylether layer was dried with anhydrous sodiumsulfate, and then the diethylether was removed to provide a crudereaction product of 2-ethoxycarbonyl-2-octyl-cyclohexanone. This crudereaction product was dissolved in 20 ml of tetrahydrofuran. A solutioncomprising 80 ml tetrahydrofuran with 2 g lithium borohydride dispersedtherein was added dropwise to the above2-ethoxycarbonyl-2-octyl-cyclohexanone solution under an iced conditionwhile stirring and the stirring was continued for 4 hours. After adding50 ml ethylacetate and 100 ml distilled water, the solution wasacidified by the addition of a 10% sulfuric acid aqueous solution togive a pH of 2. The reaction solution was extracted twice with 50 ml ofdiethylether. The diethylether layer was dried with anhydrous sodiumsulfate, and then the diethylether was removed to provide a crudereaction product of 2-hydroxymethyl-2-octyl-cyclohexanone. This crudereaction product was purified by means of silica gel columnchromatography (eluent: chloroform/methanol=97/3) and 18.3 g of2-hydroxymethyl-2-octyl-cyclohexanol was obtained as a pale yellow, oilysubstance (yield: 64.3%). In the measurement of the infrared absorptionspectrum, a strong absorption by a hydroxyl group at 3,370 cm⁻¹ and, inthe mass spectrometric measurement, a peak corresponding to the loss ofwater from the parent ion peak, were observed. Besides, in the elementalanalysis, measured values of C=74.27% and H=12.53% were found(theoretical values of C and H: C=74.33% and H=12.74%). Thus, theproduction of 2-hydroxymethyl-2-octyl-cyclohexanol was ascertained.

SYNTHESIZING EXAMPLE 7 Synthesis of 2-hydroxymethyl-2-ethyl-cyclohexanol

[0222] The same procedure as Synthesizing Example 6 was conducted,except that 12 g of ethyl bromide was used instead of 25 g of octylbromide used in Synthesizing Example 6, and 14.7 g of2-hydroxymethyl-2-ethyl-cyclohexanol was obtained as a pale yellow, oilysubstance (yield: 79%). The identification of the structure wasconducted in the same manner as Synthesizing Example 6, with theconsequence that the structure was affirmed. It was further identifiedby an elemental analysis in which measured values of C=68.13% andH=11.53% were found (theoretical values of C and H: C=68.31% andH=11.47%).

SYNTHESIZING EXAMPLE 8 Synthesis of2-hydroxymethyl-2-isopropyl-cyclohexanol

[0223] The same procedure as Synthesizing Example 6 was conducted,except that 15 g of isopropyl bromide was used instead of 25 g of octylbromide used in Synthesizing Example 6, and 14.8 g of2-hydroxymethyl-2-isopropyl-cyclohexanol was obtained as a pale yellow,oily substance (yield: 73%). The identification of the structure wasconducted in the same manner as Synthesizing Example 6, with theconsequence that the structure was supported. It was further identifiedby an elemental analysis in which measured values of C=69.77% andH=11.59% were found (theoretical values of C and H: C=69.72% andH=11.70%).

SYNTHESIZING EXAMPLE 9 Synthesis of2-hydroxymethyl-2-undecyl-cyclohexanol

[0224] The same procedure as Synthesizing Example 6 was conducted,except that 15 g of undecyl bromide was used instead of the 25 g ofoctyl bromide used in Synthesizing Example 6, and 21.2 g of2-hydroxymethyl-2-undecyl-cyclohexanol was obtained as a pale yellow,oily substance (yield: 60%). The identification of the structure wasconducted in the same manner as Synthesizing Example 6, with theconsequence that the structure was affirmed. It was further identifiedby an elemental analysis in which measured values of C=79.67% andH=12.56% were found (theoretical values of C and H: C=79.45% andH=12.83%).

SYNTHESIZING EXAMPLE 10 Synthesis of2-hydroxymethyl-2-octyl-cyclopentanol

[0225] 20 g of 2-ethoxycarbonyl-cyclopentanone was dissolved in 15 mldimethylformamide and stirred. Then, a solution comprising 200 mldimethylformamide with 6 g sodium hydride dispersed therein wasgradually added dropwise to the above 2-ethoxycarbonyl-cyclopentanonesolution. After the addition of the sodium hydride solution had beencompleted, the reaction solution was stirred for 2 hours at roomtemperature under a nitrogen gas stream. A solution comprising 15 mldimethylformamide with 25 g octyl bromide dissolved therein was furtheradded dropwise to the reaction solution. After the addition had beencompleted, the temperature was raised to 100° C. and agitation wasconducted for 2 hours. The reaction solution was cooled down, thenpoured into iced water and extraction with 100 ml diethylether wasconducted twice. The diethylether layer was dried with anhydrous sodiumsulfate, and then the diethylether was removed to provide a crudereaction product of 2-ethoxycarbonyl-2-octyl-cyclopentanone. This crudereaction product was dissolved in 20 ml of tetrahydrofuran. A solutioncomprising 80 ml tetrahydrofuran with 2 g lithium borohydride dispersedtherein was added dropwise to the above2-ethoxycarbonyl-2-octyl-cyclopentanone solution under an iced conditionwhile stirring and the stirring was further continued for 4 hours. Afteradding 50 ml ethylacetate and 100 ml distilled water, the solution wasacidified by the addition of a 10% sulfuric acid aqueous solution togive a pH of 2. The reaction solution was extracted twice with 50 ml ofdiethylether. The diethylether layer was dried with anhydrous sodiumsulfate, and then the diethylether was removed to provide a crudereaction product of 2-hydroxymethyl-2-octyl-cyclopentanone. This crudereaction product was purified by means of silica gel columnchromatography (eluent: chloroform/methanol=97/3) and 18.9 g of2-hydroxymethyl-2-octyl-cyclopentanol was obtained as a pale yellow,oily substance (yield: 64.7%). In the measurement of the infraredabsorption spectrum, a strong absorption by a hydroxyl group at 3,370cm⁻¹ and, in the mass spectrometric measurement, a peak corresponding tothe loss of water from the parent ion peak, were observed. Besides, inthe elemental analysis, measured values of C=73.37% and H=12.45% werefound (theoretical values of C and H: C=73.13% and H=12.35%). Thus, theproduction of 2-hydroxymethyl-2-octyl-cyclopentanol was ascertained.

SYNTHESIZING EXAMPLE 11 Synthesis of2-hydroxymethyl-2-ethyl-cyclopentanol

[0226] The same procedure as Synthesizing Example 10 was conducted,except that 12 g of ethyl bromide was used instead of 25 g of octylbromide used in Synthesizing Example 10, and 12.4 g of2-hydroxymethyl-2-ethyl-cyclopentanol was obtained as a pale yellow,oily substance (yield: 67%). The identification of the structure wasconducted in the same manner as Synthesizing Example 10, with theconsequence that the structure was affirmed. It was further identifiedby an elemental analysis in which measured values of C=66.50% andH=11.32% were found (theoretical values of C and H: C=66.63% andH=11.18%).

SYNTHESIZING EXAMPLE 12 Synthesis of2-hydroxymethyl-2-isopropyl-cyclopentanol

[0227] The same procedure as Synthesizing Example 10 was conducted,except that 15 g of isopropyl bromide was used instead of 25 g of octylbromide used in Synthesizing Example 10, and 12.8 g of2-hydroxymethyl-2-isopropyl-cyclopentanol was obtained as a pale yellow,oily substance (yield: 63%). The identification of the structure wasconducted in the same manner as Synthesizing Example 10, with theconsequence that the structure was affirmed. It was further identifiedby an elemental analysis in which measured values of C=68.11% andH=11.60% were found (theoretical values of C and H: C=68.31% andH=11.46%).

SYNTHESIZING EXAMPLE 13 Synthesis of2-hydroxymethyl-2-undecyl-cyclopentanol

[0228] The same procedure as Synthesizing Example 10 was conducted,except that 15 g of undecyl bromide was used instead of 25 g of octylbromide used in Synthesizing Example 10, and 24.0 g of2-hydroxymethyl-2-undecyl-cyclopentanol was obtained as a pale yellow,oily substance (yield: 66%). The identification of the structure wasconducted in the same manner as Synthesizing Example 10, with theconsequence that the structure was affirmed. It was further identifiedby an elemental analysis in which measured values of C=76.02% andH=12.81% were found (theoretical values of C and H: C=76.00% andH=12.76%).

SYNTHESIZING EXAMPLE 14 Synthesis of 2-hydroxymethyl-menthol

[0229] 8 g of sodium hydride (containing 40% of liquid paraffin) wasgradually added to 100 ml of dry benzene and 20 g of diethyl carbonatewas further added therein. Then the mixture was heated to the refluxtemperature, while stirring. A solution comprising 40 ml dry benzene and159 menthone dissolved therein was gradually added dropwise to thisreaction solution, taking about 2 hours. After the whole amount had beenadded, the heating while stirring was further continued for 2 hours.

[0230] The mixture was cooled down to room temperature and then 20 ml ofacetic acid was gradually added thereto. 100 ml of cold water wasfurther added and then the organic layer was extracted. The water layerwas extracted twice with 100 ml of benzene and then the above organiclayer was admixed. This organic layer was washed with cold water andthen dried with anhydrous sodium sulfate. Then, the benzene was removedto provide a crude reaction product. This crude reaction product wasvacuum-distilled, whereby 16 g of a fraction mainly containing2-ethoxycarbonyl-menthone was obtained.

[0231] This fraction was dissolved in 20 ml of dry tetrahydrofuran (THF)and then the resulting solution, while stirring under a cold condition,was gradually admixed dropwise to a solution comprising 120 ml dry THFwith 2 g lithium borohydride dispersed therein. After the admixing hadbeen completed, the stirring was continued for 4 hours at roomtemperature. Under cooling and stirring, 50 ml of ethyl acetate and 100ml of water were gradually added and then the solution was acidified bythe addition of a 10% sulfuric acid aqueous solution to give a pH of 2.

[0232] The reaction solution was extracted twice with 100 ml ofdiethylether and then dried with anhydrous sodium sulfate. Then, thediethylether and THF were removed to provide a crude reaction product.By purifying by means of silica gel column chromatography (eluent:benzene/acetone=8/1), 8.3 g of a colorless, oily substance was obtained(yield: 34.4%).

[0233] In the mass spectrometric measurement of the obtained oilysubstance, a peak corresponding to the loss of water from the parent ionpeak was observed. In the measurement of the infrared absorptionspectrum, a strong absorption by a hydroxyl group at 3,380 cm⁻¹ wasfound. Besides, the production of HMMO was ascertained by the elementalanalysis in which measured values of C=70.85% and H=12.01% were found(theoretical values of C and H: C=70.92% and H=11.90%).

SYNTHESIZING EXAMPLE 15 Synthesis of2-hydroxymethyl-4-(t-butyl)-cyclohexanol

[0234] 20 g of 2-ethoxycarbonyl-4-(t-butyl)-cyclohexanone was dissolvedin 20 ml tetrahydrofuran. A solution comprising 80 ml tetrahydrofuranwith 2 g lithium borohydride dispersed therein was gradually addeddropwise to the above 2-ethoxycarbonyl-4-(t-butyl)-cyclohexanonesolution while stirring under an iced condition. The stirring wascontinued for 4 hours. After adding 50 ml ethylacetate and 100 mldistilled water, the solution was acidified by the addition of a 10%sulfuric acid aqueous solution to give a pH of 2. The reaction solutionwas extracted twice with 50 ml of diethylether.

[0235] The diethylether layer was dried with anhydrous sodium sulfate,and then the diethylether was removed to provide a crude reactionproduct of 2-hydroxymethyl-4-(t-butyl)-cyclohexanol. This crude reactionproduct was purified by means of silica gel column chromatography(eluent: chloroform/methanol=97/3) and 15.3 g of2-hydroxymethyl-4-(t-butyl)-cyclohexanol was obtained as a colorless,oily substance (yield: 93%). In the measurement of the infraredabsorption spectrum, a strong absorption by a hydroxyl group at 3,370cm⁻¹ and, in the mass spectrometric measurement, a peak corresponding tothe loss of water from the parent ion peak, were observed. Besides, inthe mass spectrometric measurement of the trimethyl silyl derivative(TMS) of the obtained substance, a parent ion peak of 310 was found. Inthe elemental analysis, measured values of C=70.78% and H=11.93% werefound (theoretical values of C and H: C=70.92% and H=11.90%). Thus, theproduction of 2-hydroxymethyl-4-(t-butyl)-cyclohexanol was ascertained.

SYNTHESIZING EXAMPLE 16 Synthesis of 2-hydroxymethyl-cyclooctanol

[0236] The same procedure as Synthesizing Example 15 was conducted,except that 20 g of 2-ethoxycarbonyl-cyclooctanone was used instead of20 g of 2-ethoxycarbonyl-4-(t-butyl)-cyclohexanone used in SynthesizingExample 15, and 14.5 g of 2-hydroxymethyl-2-cyclooctanol was obtained asa colorless, oily substance (yield: 91%). The identification of thestructure was conducted by the mass spectrometric measurement in thesame manner as Synthesizing Example 15, with the consequence that thestructure was affirmed. It was further identified by an elementalanalysis in which measured values of C=67.96% and H=11.58% were found(theoretical values of C and H: C=68.31% and H=11.47%).

SYNTHESIZING EXAMPLE 17 Synthesis of2-hydroxymethyl-4-ethyl-cyclopentanol

[0237] The same procedure as Synthesizing Example 15 was conductedexcept that 20 g of 2-ethoxycarbonyl-4-ethyl-cyclopentanone was usedinstead of 20 g of 2-ethoxycarbonyl-4-(t-butyl)-cyclohexanone used inSynthesizing Example 15, and 13.6 g of2-hydroxymethyl-4-ethyl-cyclopentanol was obtained as a colorless, oilysubstance (yield: 87%). The identification of the structure wasconducted by the mass spectrometric measurement in the same manner asSynthesizing Example 15, with the consequence that the structure wasaffirmed. It was further identified by an elemental analysis in whichmeasured values of C=66.33% and H=11.41% were found (theoretical valuesof C and H: C=66.63% and H=11.18%).

SYNTHESIZING EXAMPLE 18 Synthesis of2-hydroxymethyl-3,4-dimethyl-cyclohexanol

[0238] The same procedure as Synthesizing Example 15 was conducted,except that 15 g of 2-ethoxycarbonyl-3,4-dimethyl-cyclohexanone was usedinstead of 20 g of 2-ethoxycarbonyl-4-(t-butyl)-cyclohexanone used inSynthesizing Example 15, and 9.3 g of2-hydroxymethyl-3,4-dimethyl-cyclohexanol was obtained as a colorless,oily substance (yield: 78%). The identification of the structure wasconducted by the mass spectrometric measurement in the same manner asSynthesizing Example 15, with the consequence that the structure wasaffirmed. It was further identified by an elemental analysis in whichthe values of C=68.10% and H=11.64% were found (theoretical values of Cand H: C=68.31% and H=11.47%).

SYNTHESIZING EXAMPLE 19 Synthesis of2-hydroxymethyl-4-isopropyl-6-methyl-cyclohexanol

[0239] The same procedure as Synthesizing Example 15 was conducted,except that 20 g of 2-ethoxycarbonyl-4-isopropyl-6-methyl-cyclohexanonewas used instead of 20 g of 2-ethoxycarbonyl-4-(t-butyl)-cyclohexanoneused in Synthesizing Example 15, and 13.5 g of 2-hydroxymethyl-4isopropyl-6-methyl-cyclohexanol was obtained as a colorless, oilysubstance (yield: 82%). The identification of the structure wasconducted by the mass spectrometric measurement in the same manner asSynthesizing Example 15, with the consequence that the structure wasaffirmed. It was further identified by an elemental analysis in whichmeasured values of C=70.86% and H=12.05% were found (theoretical valuesof C and H: C=70.92% and H=11.90%).

SYNTHESIZING EXAMPLE 20 Synthesis of 3-(1-hydroxyethyl)-borneol

[0240] 2.50 ml of 2.5M n-butylithium hexane solution was added dropwiseto a tetrahydrofuran solution comprising 4 ml THF and 1.00 mldiisopropylamine at −78° C. and the mixture was stirred for 15 minutes.Then, a solution comprising 4 ml THF with 0.91 g camphor dissolvedtherein was added dropwise to the above solution at −78° C., then, 0.27g of acetaldehyde was further added and the mixture was stirred for 15minutes. Thus, 3-(1-hydroxyethyl)camphor was synthesized. This reactionsolution was admixed with 50 ml of saturated sodium hydrogen carbonateaqueous solution and restored to room temperature. The reaction productwas extracted with diethylether. 5 ml of the above3-(1-hydroxyethyl)-camphor diethylether solution was gradually addeddropwise to 10 ml of a diethylether solution comprising 10 mldiethylether and 0.11 g lithium aluminum hydride and the mixture wasstirred at room temperature for 30 minutes. 0.5 ml of water and 0.5 mlof 2N—NaOH were added to the reaction solution to separate the solidsout. The separated-out solids were filtered off and the solvent wasremoved under vacuum. The residue was purified by means of silica gelcolumn chromatography (eluent: hexane/ethylacetate=7/3) and 0.75 g of3-(1-hydroxyethyl)-borneol was obtained (yield: 95%).

SYNTHESIZING EXAMPLE 21 Synthesis of 3-(1-hydroxypropyl)-borneol

[0241] Synthesis was conducted in the same procedure as SynthesizingExample 20, except that 0.35 g of propionaldehyde was used instead ofacetaldehyde and 0.79 g of 3-(1-hydroxypropyl)-camphor was obtained(yield: 63%). Successively thereafter, using 0.84 g of the3-(1-hydroxypropyl)-camphor, synthesis was conducted also in the sameprocedure as Synthesizing Example 20 and 0.80 g of3-(1-hydroxypropyl)-borneol was obtained (yield: 94%).

SYNTHESIZING EXAMPLE 22 Synthesis of3-(1-hydroxy-2-methylpropyl)-borneol

[0242] Synthesis was conducted in the same procedure as SynthesizingExample 20, except that 0.44 g of 2-methyl-propionaldehyde was usedinstead of acetaldehyde and 0.86 g of3-(1-hydroxy-2-methylpropyl)-camphor was obtained (yield: 64%).Successively thereafter, using 0.90 g of the3-(1-hydroxy-2-methylpropyl)-camphor, synthesis was conducted also inthe same procedure as Synthesizing Example 20 and 0.85 g of3-(1-hydroxy-2-methylpropyl)-borneol was obtained (yield: 94%).

SYNTHESIZING EXAMPLE 23 Synthesis of 3-(1-hydroxybutyl)-borneol

[0243] Synthesis was conducted in the same procedure as SynthesizingExample 20, except that 0.44 g of butylaldehyde was used instead ofacetaldehyde and 0.79 g of 3-(1-hydroxybutyl)-camphor was obtained(yield: 59%). Successively thereafter, using 0.90 g of the3-(1-hydroxybutyl)-camphor, synthesis was conducted also in the sameprocedure as Synthesizing Example 20 and 0.81 g of3-(1-hydroxybutyl)-borneol was obtained (yield: 90%).

SYNTHESIZING EXAMPLE 24 Synthesis of 2-hydroxymethyl-menthone

[0244] 20 g of menthone was dissolved in 50 ml of methanol and then 1.6g of potassium carbonate was admixed therewith. The reaction solutionwas heated up to 65° C. and 14 ml of formalin solution was graduallyadded dropwise thereto, while stirring. After the whole quantity of theformalin solution had been added, the stirring was continued for 3hours. Methanol was removed from this reaction solution under a vacuumand then extraction was conducted twice with 50 ml of diethylether. Thediethylether layer was dried with anhydrous sodium sulfate and thendiethylether was removed to provide a crude reaction product. This crudereaction product was purified by means of silica gel columnchromatography (eluent: benzene/acetone=8/1) and 7.3 g of a colorlessand transparent, oily substance was obtained (yield: 30.5%).

[0245] In the mass spectrometric measurement of the resulting oilysubstance, a peak corresponding to the loss of water from the parent ionpeak was observed. Besides, in the mass spectrometric measurement of thetrimethyl silyl derivative of the obtained substance, a parent ion peakof 256 was observed. In the elemental analysis, measured values ofC=71.43% and H=11.08% were found (theoretical values of C and H:C=71.69% and H=10.94%). Thus, the production of HMMT was ascertained.

SYNTHESIZING EXAMPLE 25 Synthesis of2-(1-hydroxyisopropyl)-5-methyl-cyclopentanone

[0246] 7.9 g of 2-(1-hydroxyisopropyl)-5-methyl-cyclopentanol was addeddropwise to 100 ml of a dichloromethane suspension containing 16.2 gpyridinium chlorochromate and the mixture was stirred for 5 hours atroom temperature. The reaction solution was admixed with diethyletherand stirred. Then, the chromate was filtered out and the filtrate wascondensed under a vacuum. The residue was purified by means of silicagel column chromatography (eluent: hexane/ethylacetate=7/3) and 6.6 g of2-(1-hydroxyisopropyl)-5-methyl-cyclopentanone was obtained as an oilysubstance (yield: 86%).

[0247] In the mass spectrometric measurement of the obtained oilysubstance, a molecular ion peak (M⁺) was observed. Furthermore, twopeaks corresponding to the loss of water and methyl group from theparent ion peak were observed. In the elemental analysis, measuredvalues of C=69.15% and H=10.19% were found (theoretical values of C andH: C=69.20% and H=10.32%). Besides, in the measurement of the infraredabsorption spectrum, a strong absorption by carbonyl group at 1,720 cm⁻¹was observed. From the results of the above analyses, the production of2-(1-hydroxyisopropyl)-5-methyl-cyclopentanone was ascertained.

SYNTHESIZING EXAMPLE 26 Synthesis of 8-hydroxy-2-methyl-p-menthan-3-one

[0248] 9.3 g of p-menthane-2-methyl-3,8-diol obtained in the aboveSynthesizing Example 1 was added dropwise to 100 ml of a dichloromethanesuspension containing 16.2 g pyridinium chlorochromate, and the mixturewas stirred for 5 hours at room temperature. The reaction solution wasadmixed with diethylether and stirred. Then, the chromate was filteredout and the filtrate was condensed under a vacuum. The residue waspurified by means of silica gel column chromatography (eluent:hexane/ethylacetate=4/1) and 7.9 g of 8-hydroxy-2-methyl-p-menthan-3-oneof the present invention was obtained as an oily substance (yield:85.9%).

[0249] In the mass spectrometric measurement of the obtained oilysubstance, a molecular ion peak (M⁺) and a peak corresponding to theloss of water from the parent ion peak were observed. In the elementalanalysis, measured values of C=71.68% and H=10.93% were found(theoretical values of C and H: C=71.70% and H=10.93%). Besides, in themeasurement of the infrared absorption spectrum, an absorption by ahydroxyl group at 3,400 cm⁻¹ and a strong absorption by a carbonyl groupat 1,720 cm⁻¹ were observed. From the results of the above analyses, theproduction of 8-hydroxy-2-methyl-p-menthan-3-one was ascertained. Thisproduct was substantially odorless.

SYNTHESIZING EXAMPLE 27 Synthesis of8-hydroxy-2-methylene-p-menthan-3-one

[0250] 9.2 g of p-menthane-2-methylene-3,8-diol obtained in the aboveSynthesizing Example 2 was added dropwise to 100 ml of a dichloromethanesuspension containing 16.2 g pyridinium chlorochromate, and the mixturewas stirred for 5 hours at room temperature. The reaction solution wasadmixed with diethylether and stirred. Then, the chromate was filteredout and the filtrate was condensed under a vacuum. The residue waspurified by means of silica gel column chromatography (eluent:hexane/ethylacetate=4/1) and 7.0 g of8-hydroxy-2-methylene-p-menthan-3-one of the present invention wasobtained as an oily substance (yield: 76.9%).

[0251] In the mass spectrometric measurement of the obtained oilysubstance, a molecular ion peak (M⁺) and a peak corresponding to theloss of water from the parent ion peak were observed. In the elementalanalysis, measured values of C=72.52% and H=9.90% were found(theoretical values of C and H: C=72.49% and H=9.95%). Besides, in themeasurement of the infrared absorption spectrum, an absorption by ahydroxyl group at 3,400 cm⁻¹ and a strong absorption by a carbonyl groupat 1,720 cm⁻¹ were observed. From the results of the above analyses, theproduction of 8-hydroxy-2-methylene-p-menthan-3-one was ascertained.This product was substantially odorless.

SYNTHESIZING EXAMPLE 28 Synthesis of 8-hydroxy-2-ethyl-p-menthan-3-one

[0252] 10.0 g of p-menthane-2-ethyl-3,8-diol obtained in the aboveSynthesizing Example 3 was added dropwise to 100 ml of a dichloromethanesuspension containing 16.2 g pyridinium chlorochromate, and the mixturewas stirred for 5 hours at room temperature. The reaction solution wasadmixed with diethylether and stirred. Then, the chromate was filteredout and the filtrate was condensed under vacuum. The residue waspurified by means of silica gel column chromatography (eluent:hexane/ethylacetate=4/1) and 8.2 g of 8-hydroxy-2-ethyl-p-menthan-3-oneof the present invention was obtained as an oily substance (yield:82.8%).

[0253] In the mass spectrometric measurement of the obtained oilysubstance, a molecular ion peak (M⁺) and a peak corresponding to theloss of water from the parent ion peak were observed. In the elementalanalysis, measured values of C=72.75% and H=11.22% were found(theoretical values of C and H: C=72.69% and H=11.18%). Besides, in themeasurement of the infrared absorption spectrum, an absorption by ahydroxyl group at 3,400 cm⁻¹ and a strong absorption by a carbonyl groupat 1,720 cm⁻¹ were observed. From the results of the above analyses, theproduction of 8-hydroxy-2-ethyl-p-menthan-3-one was ascertained. Thisproduct was substantially odorless.

SYNTHESIZING EXAMPLE 29 Synthesis of8-hydroxy-2-(2-propenyl)-p-menthan-3-one

[0254] 10.6 g of p-menthan-2-(2-propenyl)-3,8-diol obtained in the aboveSynthesizing Example 4 was added dropwise to 100 ml of a dichloromethanesuspension containing 16.2 g pyridinium chlorochromate, and the mixturewas stirred for 5 hours at room temperature. The reaction solution wasadmixed with diethylether and stirred. Then, the chromate was filteredout and the filtrate was condensed under a vacuum. The residue waspurified by means of silica gel column chromatography (eluent:hexane/ethylacetate=4/1) and 8.6 g of8-hydroxy-2-(2-propenyl)-p-menthan-3-one of the present invention wasobtained as an oily substance (yield: 81.9%).

[0255] In the mass spectrometric measurement of the obtained oilysubstance, a molecular ion peak (M⁺) and a peak corresponding to theloss of water from the parent ion peak were observed. In the elementalanalysis, measured values of C=74.20% and H=10.60% were found(theoretical values of C and H: C=74.25% and H=10.54%). Besides, in themeasurement of the infrared absorption spectrum, an absorption by ahydroxyl group at 3,400 cm⁻¹ and a strong absorption by a carbonyl groupat 1,720 cm⁻¹ were observed. From the results of the above analyses, theproduction of 8-hydroxy-2-(2-propenyl)-p-menthan-3-one was ascertained.This product was substantially odorless.

SYNTHESIZING EXAMPLE 30 Synthesis of 8-hydroxy-2-hexyl-p-menthan-3-one

[0256] 12.8 g of p-menthane-2-hexyl-3,8-diol obtained in the aboveSynthesizing Example 5 was added dropwise to 100 ml of a dichloromethanesuspension containing 16.2 g pyridinium chlorochromate, and the mixturewas stirred for 5 hours at room temperature. The reaction solution wasadmixed with diethylether and stirred. Then, the chromate was filteredout and the filtrate was condensed under a vacuum. The residue waspurified by means of silica gel column chromatography (eluent:hexane/ethylacetate=4/1) and 10.8 g of 8-hydroxy-2-hexyl-p-menthan-3-oneof the present invention was obtained as an oily substance (yield:85.0%).

[0257] In the mass spectrometric measurement of the obtained oilysubstance, a molecular ion peak (M⁺) and a peak corresponding to theloss of water from the parent ion peak were observed. In the elementalanalysis, measured values of C=75.50% and H=11.94% were found(theoretical values of C and H: C=75.54% and H=11.88%). Besides, in themeasurement of the infrared absorption spectrum, an absorption by ahydroxyl group at 3,400 cm⁻¹ and a strong absorption by a carbonyl groupat 1,720 cm⁻¹ were observed. From the results of the above analyses, theproduction of 8-hydroxy-2-hexyl-p-menthan-3-one was ascertained. Thisproduct was substantially odorless.

SYNTHESIZING EXAMPLE 31 Synthesis of 3-(1-hydroxyethyl)-camphor

[0258] 2.50 ml of 2.5 M n-butylithium hexane solution was added dropwisea tetrahydrofuran solution comprising 4 ml THF and 1.00 mldiisopropylamine at −78° C. and the mixture was stirred for 15 minutes.Then, a THF solution comprising 4 ml THF and 0.91 g camphor was addeddropwise to the above solution at −78° C., then the solution was furtheradmixed with 0.27 g of acetaldehyde and stirred for 15 minutes. Thisreaction solution was admixed with 50 ml of a saturated sodium hydrogencarbonate aqueous solution and restored to room temperature. Thereaction product was extracted with diethylether. The organic layer waswashed with saturated brine, dried with anhydrous sodium sulfate andthen the solvent was removed under a vacuum. The residue was purified bymeans of silica gel column chromatography (eluent:hexane/ethylacetate=8/2) and 0.94 g of 3-(1-hydroxyethyl)-camphor wasobtained (yield: 80%).

SYNTHESIZING EXAMPLE 32 Synthesis of 3-(1-hydroxypropyl)-camphor

[0259] Synthesis was conducted in the same procedure as SynthesizingExample 31, except that 0.35 g of propionaldehyde was used instead ofacetaldehyde, and 0.79 g of 3-(1-hydroxypropyl)-camphor was obtained(yield: 63%).

SYNTHESIZING EXAMPLE 33 Synthesis of3-(1-hydroxy-2-methylpropyl)-camphor

[0260] Synthesis was conducted in the same procedure as SynthesizingExample 31, except that 0.44 g of 2-methyl-propionaldehyde was usedinstead of acetaldehyde, and 0.86 g of3-(1-hydroxy-2-methylpropyl)-camphor was obtained (yield: 64%).

SYNTHESIZING EXAMPLE 34 Synthesis of 3-(1-hydroxybutyl)-camphor

[0261] Synthesis was conducted in the same procedure as SynthesizingExample 31, except that 0.44 g of butyl aldehyde was used instead ofacetaldehyde, and 0.79 g of 3-(1-hydroxybutyl)-camphor was obtained(yield: 59%).

[0262] The present invention will be illustrated by the followingexamples.

[0263] In each example, the noxious-insect repellency test was conductedas follows:

Test Method of Noxious-Insect Repelling Effect and Durability Thereof

[0264] In order to assess the repelling effect against imagoes of thetiger mosquito, Aedes albopictus, the following test was conducted at aroom temperature of 30° C. and a relative humidity of 70% in anair-conditioned room. 10 ml each of test samples was applied to left andright forearms. Each treated forearm was introduced into a wire gauzecage (20 cm L.×15 cm Dia.) containing 50 female and 50 male tigermosquitoes 5-7 days old after eclosion, for 15 minutes to afford timefor biting. The assessment was repeated 30 minutes, 1 hour, 2 hours, 4hours and 6 hours after the test sample was applied. The number of marksmade by biting within each biting time was counted and a percentrepellency was calculated using the following formula:

Percent repellency=(X−Y)/X×100(%)

[0265] X: the number of the marks made by biting when the test samplewas not applied,

[0266] Y: the number of the marks made by biting when the test samplewas applied.

EXAMPLES 1 AND 2, AND COMPARATIVE EXAMPLES 1 AND 2

[0267] (Repellent Lotion)

[0268] The p-menthane-2-methyl-3,8-diol (MMD) andp-menthane-2-methylene-3,8-diol (MMED) obtained in the foregoingSynthesizing Examples 1 and 2, respectively, were formulated accordingto the recipe shown in Table 1 below to prepare repellent lotions ofExamples 1 and 2. The noxious-insect repellency test was conducted withthese repellent lotions. The N,N-diethyltoluamide formulated inComparative Example 1 is a hitherto known compound used as anoxious-insect repellent, and the p-menthane-3,8-diol formulated inComparative Example 2 is a compound known to have an excellent repellingeffect (the same in the Comparative Examples hereinafter). TABLE 1Comparative Example Example Synthetic component 1 2 1 2 95°non-denatured alcohol 89 87 87 85 Pure water 10 10 10 10N,N-diethyltoluamide — —  3 — p-Menthane-3,8-diol — — —  3 MMD (compoundof  3 — — — Synthesizing Example 1) MMED (compound of —  3 — —Synthesizing Example 2)

[0269] With respect to the repellents of the above Examples 1 and 2 andComparative Examples 1 and 2, the noxious-insect repellency test wasconducted against the above tiger mosquito imagoes. The results areshown in Table 2. As evident from Table 2, the repellent lotions of thepresent invention, formulated with the MMD and MMED, respectively,exhibited an excellent noxious-insect repelling effect and durability.TABLE 2 After application 30 min. 1 hr. 4 hrs. 6 hrs. Example 1 100 100100 95 Example 2 100 100 100 100 Comparative 100 78 68 40 Example 1Comparative 100 85 75 35 Example 2

EXAMPLES 3, 4 AND 5, AND COMPARATIVE EXAMPLES 3 AND 4

[0270] (Repellent Lotion)

[0271] The p-menthane-2-ethyl-3,8-diol,p-menthane-2-(2-propenyl)-3,8-diol and p-menthane-2-hexyl-3,8-diolobtained in the foregoing Synthesizing Examples 3, 4 and 5,respectively, were formulated according to the recipe shown in Table 3below to prepare repellent lotions of Examples 3, 4 and 5. TABLE 3Comparative Example Example Synthetic component 3 4 3 4 5 95°non-denatured alcohol 87 87 87 87 87 Pure water 10 10 10 10 10N,N-diethyltoluamide 3 — — — — p-Menthane-3,8-diol — 3 — — —p-Menthane-2-ethyl-3,8-diol — — 3 — — p-Menthane-2-(2-propenyl)- — — — 3— 3,8-diol p-Menthane-2-hexyl-3,8-diol — — — — 3

[0272] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with these repellent lotions, and Examples 3, 4 and 5 werecompared with Comparative Examples 3 and 4. The results are shown inTable 4. As evident from Table 4, the repellent lotions of the presentinvention formulated with p-menthane-2-ethyl-3,8-diol,p-menthane-2-(2-propenyl)-3,8-diol and p-menthane-2-hexyl-3,8-diol,respectively, exhibited an excellent noxious-insect repelling effect anddurability. TABLE 4 After application 30 min. 1 hr. 4 hrs. 6 hrs.Comparative 100 78 68 40 Example 3 Comparative 100 100 75 55 Example 4Example 3 100 100 100 100 Example 4 100 100 100 100 Example 5 100 95 8795

EXAMPLES 6-9, AND COMPARATIVE EXAMPLES 5

[0273] (Repellent Lotion)

[0274] The 2-hydroxymethyl-2-ethyl-cyclohexanol,2-hydroxymethyl-2-octyl-cyclohexanol,2-hydroxymethyl-2-isopropyl-cyclohexanol and2-hydroxymethyl-2-undecyl-cyclohexanol obtained in the foregoingSynthesizing Examples 6-9, respectively, were formulated according tothe recipe shown in Table 5 below to prepare repellent lotions ofExamples 6-9, and the noxious-insect repellency test was conducted.TABLE 5 Comparative Example Example Synthetic component 5 6 7 8 9 95°non-denatured alcohol 87 87 87 87 87 Pure water 10 10 10 10 10N,N-diethyltoluamide 3 — — — — 2-Hydroxymethyl-2-ethyl- — 3 — — —cyclohexanol 2-Hydroxymethyl-2-octyl- — — 3 — — cyclohexanol2-Hydroxymethyl-2- — — 3 isopropyl-cyclohexanol2-Hydroxymethyl-2-undecyl- — — — 3 cyclohexnol

[0275] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with these repellent lotions, and Examples 6-9 werecompared with Comparative Example 5. The results are shown in Table 6.As evident from Table 6, the repellent lotions of the present inventionformulated with 2-hydroxymethyl-2-ethyl-cyclohexanol,2-hydroxymethyl-2-octyl-cyclohexanol,2-hydroxymethyl-2-isopropyl-cyclohexanol and2-hydroxymethyl-2-undecyl-cyclohexanol, respectively, exhibited anexcellent noxious-insect repelling effect and durability. TABLE 6 Afterapplication 30 min. 1 hr. 4 hrs. 6 hrs. Comparative 100 78 68 40 Example5 Example 6 100 100 100 88 Example 7 100 100 100 100 Example 8 100 100100 100 Example 9 100 96 94 96

EXAMPLES 10-13, AND COMPARATIVE EXAMPLES 6

[0276] (Repellent Lotion)

[0277] The 2-hydroxymethyl-2-ethyl-cyclopentanol,2-hydroxymethyl-2-octyl-cyclopentanol,2-hydroxymethyl-2-isopropyl-cyclopentanol and2-hydroxymethyl-2-undecyl-cyclopentanol obtained in the foregoingSynthesizing Examples 10-13, respectively, were formulated according tothe recipe shown in Table 7 below to prepare repellent lotions ofExamples 10-13, and the noxious-insect repellency test was conducted.TABLE 7 Comparative Example Example Synthetic component 6 10 11 12 1395° non-denatured alcohol 87 87 87 87 87 Pure water 10 10 10 10 10N,N-diethyltoluamide 3 — — — — 2-Hydroxymethyl-2-ethyl- — 3 — — —cyclopentanol 2-Hydroxymethyl-2-octyl- — — 3 — — cyclopentanol2-Hydroxymethyl-2- — — 3 isopropyl-cyclopentanol2-Hydroxymethyl-2-undecyl- — — — 3 cyclopentanol

[0278] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with these repellent lotions, and Examples 10-13 werecompared with Comparative Example 6. The results are shown in Table 8.As evident from Table 8, the repellent lotions of the present inventionformulated with 2-hydroxymethyl-2-ethyl-cyclopentanol,2-hydroxymethyl-2-octyl-cyclopentanol,2-hydroxymethyl-2-isopropyl-cyclopentanol and2-hydroxymethyl-2-undecyl-cyclopentanol, respectively, exhibited anexcellent noxious-insect repelling effect and durability. TABLE 8 Afterapplication 30 min. 1 hr. 4 hrs. 6 hrs. Example 10 100 100 100 70Example 11 100 100 100 100 Example 12 100 100 100 100 Example 13 96 9296 94 Comparative 100 78 68 40 Example 6

EXAMPLE 14 AND COMPARATIVE EXAMPLE 7

[0279] (Repellent Lotion)

[0280] The 2-hydroxymethyl-menthol (HMMO) obtained in the foregoingSynthesizing Example 14 was formulated according to the recipe shown inTable 9 below to prepare a repellent lotion of Example 14. TABLE 9Comparative Example Example 14 7 95° non-denatured alcohol 87 87 Purewater 10 10 N,N-diethyltoluamide —  3 HMMO  3 —

[0281] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with the repellent lotions, and Example 14 was comparedwith Comparative Example 7. The results are shown in Table 10. Asevident from Table 10, the repellent lotion of the present inventionformulated with HMMO exhibited an excellent noxious-insect repellingeffect and durability. TABLE 10 After application 30 min. 1 hr. 4 hrs. 6hrs. Example 14 100 100 100 100 Comparative 100  78  68  40 Example 7

EXAMPLES 15-18, AND COMPARATIVE EXAMPLES 8

[0282] (Repellent Lotion)

[0283] The 2-hydroxymethyl-4-(t-butyl)-cyclohexanol,2-hydroxymethyl-cyclooctanol, 2-hydroxymethyl-4-ethyl-cyclopentanol and2-hydroxymethyl-4-isopropyl-6-methyl-cyclohexanol obtained in theforegoing Synthesizing Examples 15-17 and 19, respectively, wereformulated according to the recipe shown in Table 11 below to preparerepellent lotions of Examples 15-18, and the noxious-insect repellencytest was conducted. TABLE 11 Comparative Example Example 8 15 16 17 1895° non-denatured alcohol 87 87 87 87 87 Pure water 10 10 10 10 10N,N-diethyltoluamide 3 — — — — 2-Hydroxymethyl-4-(t-butyl)- — 3 — — —cyclohexanol 2-Hydroxymethyl-cyclooctanol — — 3 — —2-Hydroxymethyl-4-ethyl- — — — 3 — cyclopentanol2-Hydroxymethyl-4-isopropyl- — — — — 3 6-methyl-cyclohexanol

[0284] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with the above repellent lotions, and Examples 15-18 werecompared with Comparative Example 8. The results are shown in Table 12.As evident from Table 12, the repellent lotions of the present inventionformulated with 2-hydroxymethyl-2-ethyl-cyclopentanol,2-hydroxymethyl-4-(t-butyl)cyclohexanol, 2-hydroxymethyl-cylooctanol,2-hydroxymethyl-4-ethyl-cyclopentanol and2-hydroxymethyl-4-isopropyl-6-methyl-cyclohexanol, respectively,exhibited an excellent noxious-insect repelling effect and durability.TABLE 12 After application 30 min. 1 hr. 4 hrs. 6 hrs. Comparative 10078 68 40 Example 8 Example 15 100 100 100 86 Example 16 100 100 100 100Example 17 100 100 86 74 Example 18 100 100 100 100

EXAMPLE 19 AND COMPARATIVE EXAMPLE 9

[0285] (Repellent Lotion)

[0286] The 2-hydroxymethyl-menthone (HMMT) obtained in the foregoingSynthesizing Example 24 was formulated according to the recipe shown inTable 13 below to prepare the repellent lotion of the present invention.The 2-ethyl-1,3-hexanediol formulated in Comparative Example 9 is aknown compound which is said to have an excellent repelling effect.TABLE 13 Comparative Example Example Synthetic component 19 9 95°non-denatured alcohol 87 87 Pure water 10 10 2-Ethyl-1,3-hexanediol —  3HMMT  3 —

[0287] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with these repellent lotions, and Example 19 was comparedwith Comparative Example 9. The results are shown in Table 14. Asevident from Table 14, the repellent lotion of the present inventionformulated with HMMT exhibited an excellent noxious-insect repellingeffect and durability. TABLE 14 After application 30 min. 1 hr. 4 hrs. 6hrs. Example 19 100 100 100 95 Comparative  95  85  70 20 Example 9

EXAMPLES 20-23 AND COMPARATIVE EXAMPLE 10

[0288] (Repellent Lotion)

[0289] The repellent lotions of Examples 20-23 and Comparative Example10 were prepared according to the recipe shown in Table 15 and thenoxious-insect repellency test was conducted. TABLE 15 ComparativeExample Example Synthetic component 10 20 21 22 23 95° non-denaturedalcohol 87 87 87 87 87 Pure water 10 10 10 10 10 N,N-diethyltoluamide 3— — — — 2-(1-Hydroxyethyl)-4-methyl- — 3 — — — cyclohexanol2-(1-Hydroxyethyl)- — — 3 — 1 cyclooctanol 2-(1-Hydroxybutyl)-3-ethyl- —— — 3 1 cyclopentanol 2-(1-Hydroxyethyl)- — — — — 1 cyclodecanol

[0290] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with the repellent lotions of Examples 20-23 andComparative Example 10, and these examples were compared with eachother. The results are shown in Table 16. TABLE 16 After application 30min. 1 hr. 4 hrs. 6 hrs. Comparative 100 78 68 40 Example 10 Example 20100 100 100 96 Example 21 100 100 84 78 Example 22 100 100 100 100Example 23 100 100 100 100

[0291] As evident from Table 16, the repellent lotions of the presentinvention containing 2-(1-hydroxyethyl)-4-methyl-cyclohexanol,2-(1-hydroxyethyl)-cyclooctanol,2-(1-hydroxybutyl)-3-ethyl-cyclopentanol and2-(1-hydroxyethyl)-cyclodecanol 4-methyl-cyclohexanol, respectively,exhibited an excellent noxious-insect repelling effect and durability.

EXAMPLES 24-26 AND COMPARATIVE EXAMPLE 11

[0292] (Milky Lotion)

[0293] The milky lotions of Examples 24-26 and Comparative Example 11were prepared according to the recipe shown in Table 17 and thenoxious-insect repellency test was conducted. TABLE 17 ComparativeExample Example 11 24 25 26 Vaseline 2.0 2.0 2.0 2.0 Cetanol 1.0 1.0 1.01.0 1,3-Butylene glycol 6.0 6.0 6.0 6.0 Sodium N-acylglutamate 1.0 1.01.0 1.0 Carboxyvinyl polymer 0.2 0.2 0.2 0.2 N,N-diethyltoluamide 5.0 —— — 2-(1-Hydroxypropyl)-4- — 5.0 — — methyl-cyclohexanol2-(1-Hydroxyethyl)- — — 5.0 — cycloheptanol 2-(1-Hydroxyethyl)-3,4- — —— 5.0 dimethyl-cyclohexanol Pure water Balance Balance Balance Balance

[0294] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with the milky lotions of Examples 24-26 and ComparativeExample 11, and these examples were compared with each other. Theresults are shown in Table 18. TABLE 18 After application 30 min. 1 hr.4 hrs. 6 hrs. Comparative 100 100 74 52 Example 11 Example 24 100 100100 100 Example 25 100 100 100 68 Example 26 100 100 100 100

[0295] As evident from Table 18, the milky lotions of the presentinvention containing 2-(1-hydroxypropyl)-4-methyl-cyclohexanol,2-(1-hydroxyethyl)-cycloheptanol and2-(1-hydroxyethyl)-3,4-dimethyl-cyclohexanol, respectively, exhibited anexcellent noxious-insect repelling effect and durability.

EXAMPLES 27-32 AND COMPARATIVE EXAMPLE 12

[0296] (Repellent Lotion)

[0297] The 3-(1-hydroxypropyl)-borneol, 3-(1-hydroxyethyl)-borneol,3-(1-hydroxybutyl)-borneol and 3-(1-hydroxy-2-methylpropyl)-borneolobtained by the foregoing Synthesizing Examples 20-23, respectively,were formulated according to the recipe shown in Table 19 below toprepare the repellent lotions of Examples 27-32 of the presentinvention. The noxious-insect repellency test was conducted. TABLE 19Comparative Example Example 12 27 28 29 30 31 32 95° non-denaturedalcohol 87 87 87 87 87 87 87 Pure water 10 10 10 10 10 10 10N,N-diethyltoluamide 3 — — — — — — 3-(1-Hydroxymethyl)- — 3 — — — 2 —borneol 3-(1-Hydroxyethyl)- — — 3 — — 1 1.5 borneol 3-(1-Hydroxybutyl)-— — — 3 — — 1.5 borneol 3-(1-Hydroxy-2- — — — — 3 — —methylpropyl)-borneol

[0298] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with these repellent lotions, and Examples 27-32 werecompared with Comparative Example 12. The results are shown in Table 20.TABLE 20 After application 30 min. 1 hr. 4 hrs. 6 hrs. Comparative 100100 68 40 Example 11 Example 27 100 100 100 95 Example 28 100 100 100 93Example 29 100 100 97 90 Example 30 100 100 95 89 Example 31 100 100 10095 Example 32 100 100 99 92

[0299] As evident from Table 20, the repellent lotions of the presentinvention containing 3-(1-hydroxypropyl)-borneol,3-(1-hydroxyethyl)-borneol, 3-(1-hydroxybutyl)-borneol and3-(1-hydroxy-2-methylpropyl)-borneol, respectively, exhibited anexcellent noxious-insect repelling effect and durability.

EXAMPLES 33-36 AND COMPARATIVE EXAMPLE 13

[0300] (Milky Lotion)

[0301] The 3-(1-hydroxyethyl)-borneol, 3-(1-hydroxypropyl)-borneol and3-(1-hydroxybutyl)-borneol obtained in the foregoing SynthesizingExamples 20, 21 and 23, respectively, were formulated according to therecipe shown in Table 21 below to prepare the milky lotions of Examples33-36. The noxious-insect repellency test was conducted. TABLE 21Compar- ative Example Example Synthetic component 13 33 34 35 36Vaseline 2.0 2.0 2.0 2.0 2.0 Cetanol 1.0 1.0 1.0 1.0 1.0 1,3-Butyleneglycol 6.0 6.0 6.0 6.0 6.0 Sodium N- 1.0 1.0 1.0 1.0 1.0 acylglutamateCarboxyvinyl polymer 0.2 0.2 0.2 0.2 0.2 N,N-diethyltoluamide 5.0 — — —— 3-(1-Hydroxyethyl)- — 5.0 — — 3.0 borneol 3-(1-Hydroxypropyl)- — — 5.0— 2.0 borneol 3-(1-Hydroxybutyl)- — — — 5.0 — borneol Pure water BalanceBalance Balance Balance Balance

[0302] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with these milky lotions, and Examples 33-36 were comparedwith Comparative Example 13. The results are shown in Table 22. TABLE 22After application 30 min. 1 hr. 4 hrs. 6 hrs. Comparative 100 100 74 52Example 13 Example 33 100 100 100 99 Example 34 100 100 100 93 Example35 100 100 100 91 Example 36 100 100 100 93

[0303] As evident from Table 22, the milky lotions of the presentinvention containing 3-(1-hydroxyethyl)-borneol,3-(1-hydroxypropyl)-borneol and 3-(1-hydroxybutyl)-borneol,respectively, exhibited an excellent noxious-insect repelling effect anddurability.

EXAMPLES 37 AND 38, AND COMPARATIVE EXAMPLES 14 AND 15

[0304] (Repellent Lotion)

[0305] The 2-(1-hydroxyisopropyl)-5-methyl-cyclopentanone obtained inthe foregoing Synthesizing Example 25 was formulated according to therecipe shown in Table 23 below to prepare the repellent lotions ofExamples 37 and 38. The noxious-insect repellency test was conducted.TABLE 23 Comparative Example Example Synthetic component 37 38 14 15 95°non-denatured alcohol 89 87 87 85 Pure water 10 10 10 10N,N-diethyltoluamide — —  3  5 Compound of Synthesizing  1  3 — —Example 25

[0306] The results of the noxious-insect repellency test are shown inTable 24. As evident from Table 24, the repellent lotions of the presentinvention containing 2-(1-hydroxyisopropyl)-5-methyl-cyclopentanoneexhibited an excellent noxious-insect repelling effect and durability.TABLE 24 After application 30 min. 1 hr. 4 hrs. 6 hrs. Example 37 100100 83 72 Example 38 100 100 89 80 Comparative 100 78 68 40 Example 14Comparative 100 85 70 55 Example 15

EXAMPLES 39-43 AND COMPARATIVE EXAMPLES 16 AND 17

[0307] (Repellent Lotion)

[0308] The 8-hydroxy-2-methyl-p-menthan-3-one,8-hydroxy-2-methylene-p-menthan-3-one,8-hydroxy-2-ethyl-p-menthan-3-one, 8-hydroxy-2-propenyl-p-menthan-3-oneand 8-hydroxy-2-hexyl-p-menthan-3-one obtained in the foregoingSynthesizing Examples 26-30, respectively, were formulated according tothe recipe shown in Table 25 below to prepare the repellent lotions ofExamples 39-43. The noxious-insect repellency test was conducted. TABLE25 Comparative Example Example Synthetic component 39 40 41 42 43 16 1795° non-denatured alcohol 87 87 87 87 87 87 87 Pure water 10 10 10 10 1010 10 N,N-diethyltoluamide — — — — — 3 — p-Menthane-3,8-diol — — — — — —3 Compound of Synthesizing 3 — — — — — — Example 26 Compound ofSynthesizing — 3 — — — — — Example 27 Compound of Synthesizing — — 3 — —— — Example 28 Compound of Synthesizing — — — 3 — — — Example 29Compound of Synthesizing — — — — 3 — — Example 30

[0309] The results of the noxious-insect repellency test are shown inTable 26. As evident from Table 26, the repellent lotions of the presentinvention containing the 8-hydroxy-p-menthan-3-one derivative of thepresent invention exhibited an excellent noxious-insect repelling effectand durability. TABLE 26 After application 30 min. 1 hr. 4 hrs. 6 hrs.Example 39 100 100 93 88 Example 40 100 100 95 91 Example 41 100 100 10098 Example 42 100 100 100 97 Example 43 100 98 93 87 Comparative 100 7868 40 Example 16 Comparative 100 100 75 55 Example 17

EXAMPLES 44-47 AND COMPARATIVE EXAMPLE 18

[0310] (Repellent Lotion)

[0311] The repellent lotions of Examples 44-47 and Comparative Example18 were prepared according to the recipe shown in Table 27 and thenoxious-insect repellency test was conducted. TABLE 27 ComparativeExample Example Synthetic component 18 44 45 46 47 95° non-denaturedalcohol 87 87 87 87 87 Pure water 10 10 10 10 10 N,N-diethyltoluamide 3— — — — 2-Hydroxymethyl-4-(t-butyl)- — 3 — — 1 cyclohexanone2-Hydroxymethyl-cyclooctanone — — 3 — — 2-Hydroxymethyl-4-ethyl- — — — 3— cyclopentane 2-Hydroxymethyl-4-isopropyl- — — — — 26-methyl-cyclohexanone

[0312] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with the repellent lotions of Examples 44-47 andComparative Example 17, and compared with each other. The results areshown in Table 28. TABLE 28 After application 30 min. 1 hr. 4 hrs. 6hrs. Comparative 100 78 68 40 Example 18 Example 44 100 94 94 88 Example45 100 100 100 94 Example 46 100 100 86 74 Example 47 100 100 100 100

[0313] As evident from Table 28, the repellent lotions of the presentinvention containing 2-hydroxymethyl-4-(t-butyl)-cyclohexanone,2-hydroxymethyl-cyclooctanone, 2-hydroxymethyl-4-ethyl-cyclopentanoneand 2-hydroxymethyl-4-isopropyl-6-methyl-cyclohexanone, respectively,exhibited an excellent noxious-insect repelling effect and durability.

EXAMPLES 48-50 AND COMPARATIVE EXAMPLE 19

[0314] (Milky Lotion)

[0315] The milky lotions of Examples 48-50 and Comparative Example 19were prepared according to the recipe shown in Table 29 and thenoxious-insect repellency test was conducted. TABLE 29 ComparativeExample Example Synthetic component 19 48 49 50 Vaseline 2.0 2.0 2.0 2.0Cetanol 1.0 1.0 1.0 1.0 1,3-Butylene glycol 6.0 6.0 6.0 6.0 SodiumN-acylglutamate 1.0 1.0 1.0 1.0 Carboxyvinyl polymer 0.2 0.2 0.2 0.2N,N-diethyltoluamide 5.0 — — — 2-Hydroxymethyl-4- — 5.0 — 1.0methyl-cyclohexanone 2-Hydroxymethyl-3,4- — — 5.0 1.0dimethyl-cyclohexanone 2-Hydroxymethyl- — — — 3.0 cyclododecanone Purewater Balance Balance Balance Balance

[0316] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with the milky lotions of Examples 48-50 and ComparativeExample 19, and these examples were compared with each other. Theresults are shown in Table 30. TABLE 30 After application 30 min. 1 hr.4 hrs. 6 hrs. Comparative Example 19 100 100 74 52 Example 48 100 100 9486 Example 49 100 100 96 84 Example 50 100 96 86 74

[0317] As evident from Table 30, the milky lotions of the presentinvention containing 2-hydroxymethyl-4-methyl-cyclohexanone,2-hydroxymethyl-3,4-dimethyl-cyclohexanone and2-hydroxymethyl-cyclododecanone, respectively, exhibited an excellentnoxious-insect repelling effect and durability.

EXAMPLES 51-54 AND COMPARATIVE EXAMPLE 20

[0318] (Repellent Lotion)

[0319] The repellent lotions of Examples 51-54 and Comparative Example20 were prepared according to the recipe shown in Table 31 and thenoxious-insect repellency test was conducted. TABLE 31 ComparativeExample Example Synthetic component 20 51 52 53 54 95° non-denaturedalcohol 87 87 87 87 87 Pure water 10 10 10 10 10 N,N-diethyltoluamide 3— — — — 2-(1-Hydroxyethyl-4-methyl- — 3 — — 1 cyclohexanone2-(1-Hydroxyethyl)- — — 3 — — cyclooctaneone 2-(1-Hydroxybutyl)-3-ethyl-— — — 3 — cyclopentanone 2-(1-Hydroxyethyl)- — — — — 2 cyclodecanone

[0320] The noxious-insect repellency tests against tiger mosquitoimagoes were conducted with the repellent lotions of Examples 51-54 andComparative Example 20, and compared with each other. The results areshown in Table 32. TABLE 32 After application 30 min. 1 hr. 4 hrs. 6hrs. Comparative Example 20 100 100 68 40 Example 51 100 100 94 82Example 52 100 100 100 100 Example 53 100 100 98 86 Example 54 100 100100 100

[0321] As evident from Table 32, the repellent lotions of the presentinvention containing 2-(1-hydroxyethyl)-4-methyl-cyclohexanone,2-(1-hydroxyethyl)-cyclooctanone,2-(1-hydroxybutyl)-3-ethyl-cyclopentanone and2-(1-hydroxyethyl)-cyclodecanone, respectively, exhibited an excellentnoxious-insect repelling effect and durability.

EXAMPLES 55-57 AND COMPARATIVE EXAMPLE 21

[0322] (Milky Lotion)

[0323] The milky lotions of Examples 55-57 and Comparative Example 21were prepared according to the recipe shown in Table 33 and thenoxious-insect repellency test was conducted. TABLE 33 ComparativeExample Example Synthetic component 21 55 56 57 Vaseline 2.0 2.0 2.0 2.0Cetanol 1.0 1.0 1.0 1.0 1,3-Butylene glycol 6.0 6.0 6.0 6.0 SodiumN-acylglutamate 1.0 1.0 1.0 1.0 Carboxyvinyl polymer 0.2 0.2 0.2 0.2N,N-diethyltoluamide 5.0 — — — 2-(1-Hydroxyamyl)4- — 5.0 — —methyl-cyclohexanone 2-(1-Hydroxyethyl)- — — 5.0 1.0 cycloheptanone2-(1-Hydroxyethyl)-3,4- — — — 4.0 dimethyl-cyclohexanone Pure waterBalance Balance Balance Balance

[0324] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with the milky lotions of Examples 55-57 and ComparativeExample 21, and these examples were compared with each other. Theresults are shown in Table 34. TABLE 34 After application 30 min. 1 hr.4 hrs. 6 hrs. Comparative Example 21 100 100 74 52 Example 55 100 100100 84 Example 56 100 100 100 90 Example 57 100 100 100 96

[0325] As evident from Table 34, the milky lotions of the presentinvention containing 2-(1-hydroxyamyl)-4-methyl-cyclohexanone,2-(1-hydroxyethyl)-cycloheptanone and2-(1-hydroxyethyl)-3,4-dimethyl-cyclohexanone, respectively, exhibitedan excellent noxious-insect repelling effect and durability.

EXAMPLES 58-63 AND COMPARATIVE EXAMPLE 22

[0326] (Repellent Lotion)

[0327] The 3-(1-hydroxymethyl)-camphor, 3-(1-hydroxyethyl)-camphor,3-(1-hydroxybutyl)-camphor and 3-(1-hydroxy-2-methylpropyl)-camphorobtained in the foregoing Synthesizing Examples 31-34, respectively,were formulated according to the recipe shown in Table 35 below toprepare the repellent lotions of Examples 58-63 and Comparative Example22. The noxious-insect repellency test was conducted. TABLE 35Comparative Example Example Synthetic component 22 58 59 60 61 62 63 95°non-denatured alcohol 87 87 87 87 87 87 87 Pure water 10 10 10 10 10 1010 N,N-diethyltoluamide 3 — — — — — — 3-(1-Hydroxymethyl)- — 3 — — — 2 —camphor 3-(1-Hydroxyethyl)- — — 3 — — 1 1.5 camphor 3-(1-Hydroxybutyl)-— — — 3 — — 1.5 camphor 3-(1-Hydroxy-2- — — — — 3 — —methylpropyl)-camphor Unit: wt. %

[0328] The noxious-insect repellency test against tiger mosquito imagoeswas conducted with the repellent lotions of Examples 58-63 andComparative Example 22, and these examples were compared with eachother. The results are shown in Table 36. TABLE 36 After application 30min. 1 hr. 4 hrs. 6 hrs. Comparative Example 22 100 100 68 40 Example 58100 100 99 96 Example 59 100 100 100 97 Example 60 100 100 100 100Example 61 100 100 100 100 Example 62 100 100 100 97 Example 63 100 100100 99

[0329] As evident from Table 36, the repellent lotions of the presentinvention containing 3-(1-hydroxymethyl)camphor,3-(1-hydroxyethyl)-camphor, 3-(1-hydroxybutyl)-camphor and3-(1-hydroxy-2-methylpropyl)-camphor, respectively, exhibited anexcellent noxious-insect repelling effect and durability.

EXAMPLES 64-67 AND COMPARATIVE EXAMPLE 23

[0330] (Milky Lotion)

[0331] The milky lotions of Examples 64-67 and Comparative Example 23were prepared according to the recipe shown in Table 37 and thenoxious-insect repellency test was conducted. TABLE 37 ComparativeSynthetic Example Example component 23 64 65 66 67 Vaseline 2.0 2.0 2.02.0 2.0 Cetanol 1,3-Butylene glycol 6.0 6.0 6.0 6.0 6.0 Sodium N- 1.01.0 1.0 1.0 1.0 acylglutamate Carboxyvinyl 0.2 0.2 0.2 0.2 0.2 polymerN,N-diethyl- 5.0 — — — — toluamide 3-(1-Hydroxy- — 5.0 — — 3.0 methyl)-camphor 3-(1-Hydroxyethyl)- — — 5.0 2.0 2.0 camphor 3-(1-Hydroxy- — — —5.0 — buthyl)- camphor Pure water Balance Balance Balance BalanceBalance Unit: wt. %

[0332] The noxious-insect repellency tests against tiger mosquitoimagoes were conducted with the milky lotions of Examples 64-67 andComparative Example 23, and compared with each others. The results areshown in Table 38. TABLE 38 After application 30 min. 1 hr. 4 hrs. 6hrs. Comparative Example 23 100 100 74 52 Example 64 100 100 100 84Example 65 100 100 100 100 Example 66 100 100 100 100 Example 67 100 100100 91

[0333] As evident from Table 38, the milky lotions of the presentinvention containing 3-(1-hydroxyethyl)-camphor,3-(1-hydroxypropyl)-camphor and 3-(1-hydroxybutyl)-camphor,respectively, exhibited an excellent noxious-insect repelling effect anddurability.

EXAMPLES 68-72 AND COMPARATIVE EXAMPLE 24

[0334] (Repellent Lotion)

[0335] 2-Hydroxymethyl-cyclohexanol and2-hydroxymethyl-2-alkyl-cyclohexanol derivatives having straight chainsaturated hydrocarbon radicals having 2, 4, 6, 8 and 14 carbon atoms,respectively, substituting at the second carbon atom of the cyclohexanering were synthesized in the same procedure as Synthesizing Example 6.Then, these compounds were dissolved in a 40 wt. % ethanol aqueoussolution to prepare the repellent lotions Examples 68-72 and ComparativeExample 24. The repellent lotions of Examples 68-72 contained2-hydroxymethyl-cyclohexanol and the above2-hydroxymethyl-2-(C₂₋₈-alkyl)-cyclohexanol, respectively, and therepellent lotion of Comparative Example 24 contained the above2-hydroxymethyl-2-tetradecyl(C₁₄-alkyl)-cyclohexanol, in an amount of 1%by weight. The noxious-insect repellency test was conducted with theserepellent lotions. The results (the initial activity and the durabilityof the repelling effect) are shown in Table 39. From these results, itwas found that the compounds having a substituent alkyl group of 8 orless carbon atoms exhibited a strong initial activity and the compoundshaving a substituent alkyl group of 14 or more carbon atoms did not showthe repelling effect. Thus, it was demonstrated that the repellingeffect depends upon the chain length of the substituent alkyl group.TABLE 39 After application 30 min. 1 hr. 2 hrs. 3 hrs. Example 68 100 9652 32 Example 69 100 100 100 88 Example 70 98 100 96 98 Example 71 94 9296 94 Example 72 88 86 88 90 Comparative Example 24 10 12 14 10

EXAMPLES 73-75 AND COMPARATIVE EXAMPLE 25

[0336] (Repellent Lotion)

[0337] 2-Hydroxymethyl-2-ethyl-cycloalkanol derivatives comprising 5, 8,12 and 15-membered cycloalkane, respectively, were synthesized in thesame procedure as Synthesizing Example 7. Then, these compounds weredissolved in a 40 wt. % ethanol aqueous solution to prepare therepellent lotions of Examples 73-75 and Comparative Example 25. Therepellent lotions of Examples 73-75 contained the above cycloalkanolderivatives comprising 5-12-membered cycloalkane, respectively, andComparative Example 25 contained the above cycloalkanol derivativecomprising 15-membered cycloalkane, in an amount of 1% by weight.

[0338] The noxious-insect repellency test was conducted with theserepellent lotions. The results (the initial activity and the durabilityof the repelling effect) are shown in Table 40. From these results, itwas found that the repelling effect depends upon the ring-member carbonatom number. Namely, it has been demonstrated that when the ring-membercarbon atom number is 12 or less, a strong repelling effect is exhibitedand when the ring-member carbon atom number is 15 or more, the repellingeffect is not exhibited. TABLE 40 After application 30 min. 1 hr. 2 hrs.3 hrs. Example 73 100 88 42 26 Example 74 100 100 100 94 Example 75 8684 86 88 Comparative Example 25 14 12 26 20

COMPARATIVE EXAMPLE 26

[0339] (Repellent Lotion)

[0340] The repellent lotion of Comparative Example 26 was prepared whichcontained 1% by weight of 3-(1-hydroxyhexyl)-camphor synthesizedaccording to Synthesizing Examples 31-34. With respect to thenoxious-insect repelling effect, a comparative test was conducted withthe repellent lotions of Comparative Example 26 and Examples 58, 59 and61. The results are shown in Table 41. From the results, it has beenfound that the derivative having a hydroxyhexyl group does not exhibitthe repelling effect and that the chain length of the alkyl group issignificant for the repelling effect (the initial activity and thedurability of the effect). TABLE 41 After application 30 min. 1 hr. 2hrs. 3 hrs. Example 58 100 100 98 78 Example 59 100 100 100 88 Example61 96 100 98 100 Comparative Example 26 16 16 14 16

EXAMPLE 76

[0341] With the purpose of investigating the properties of the compoundsto be used for the present invention, solubilities in a 90 wt. % ethanolaqueous solution and stabilities at 0° C., room temperature and 40° C.,of hydroxymethyl-menthol, 2-hydroxymethyl-2-butyl-cyclopentanol and2-(1-hydroxyisopropyl)-5,6-dimethyl-cyclohexanone, were investigated.The method of assessment is shown in Table 42. Besides, the results ofthe investigation are shown in Tables 43-45. As shown in Table 43, whenthe noxious-insect repellent composition contains a repellent compoundin an amount of at least 90% by weight, it has been found that thestability of the lotion is questioned. Furthermore, it can be understoodthat the quantity of the repellent compound is preferred to be at most20% by weight, in view of touch in use. TABLE 42 Method of assessmentSolubility Stability Result of assessment Soluble Stable ◯ InsolublePrecipitated X

[0342] TABLE 43 Hydroxymethyl-menthol content (wt. %) 10% 20% 50% 90%95%  0° C. Solubility ◯ ◯ ◯ ◯ ◯ Stability ◯ ◯ ◯ X X Room Solubility ◯ ◯◯ ◯ ◯ temperature Stability ◯ ◯ ◯ ◯ X 40° C. Solubility ◯ ◯ ◯ ◯ ◯Stability ◯ ◯ ◯ ◯ ◯

[0343] TABLE 44 2-Hydroxymethyl-2-butyl-cyclopentanol content (wt. %)10% 20% 50% 90% 95%  0° C. Solubility ◯ ◯ ◯ ◯ ◯ Stability ◯ ◯ ◯ ◯ X RoomSolubility ◯ ◯ ◯ ◯ ◯ temperature Stability ◯ ◯ ◯ ◯ X 40° C. Solubility ◯◯ ◯ ◯ ◯ Stability ◯ ◯ ◯ ◯ ◯

[0344] TABLE 45 2-(1-Hydroxyisopropyl)-5,6-dimethyl- cyclohexanonecontent (wt. %) 10% 20% 50% 90% 95%  0° C. Solubility ◯ ◯ ◯ ◯ ◯Stability ◯ ◯ ◯ ◯ X Room Solubility ◯ ◯ ◯ ◯ ◯ temperature Stability ◯ ◯◯ ◯ X 40° C. Solubility ◯ ◯ ◯ ◯ ◯ Stability ◯ ◯ ◯ ◯ ◯

EXAMPLE 77

[0345] With the purpose of finding the lower limit of the content,hydroxymethyl-menthol, 2-hydroxymethyl-2-butyl-cyclopentanol and2-(1-hydroxyisopropyl)-5,6-dimethyl-cyclohexanone were dissolved in a 40wt. % ethanol aqueous solution, respectively. An hour after application,the noxious-insect repellency test was conducted. The percentrepellencies are shown in Table 46. From these results, it has beenfound that the content of at least 0.1%, preferably at least 3%, byweight, of the repellent compound is required for achieving the initialactivity and the durability of the effect. Content (wt. %) 0.05% 0.1% 1%3% Hydroxymethyl-menthol 18 48 78 92 2-Hydroxymethyl-2-butyl- X 24 60 88cyclopentanol 2-(1-Hydroxyisopropyl)-5,6- X 30 70 94dimethyl-cyclohexanone

INDUSTRIAL APPLICABILITY

[0346] As explained above, the noxious-insect repellents according tothe present invention exhibit an excellent noxious-insect repellingeffect and durability. Besides, since they are substantially odorless,the noxious-insect repellents of the present invention do not give theusers unpleasant feelings. Furthermore, the repellents of the invention,since they repel noxious-insects such as mosquitoes conveying pathogenicmicrobes, are effective for preventing malaria or other diseases, and,therefore, very useful.

1. A noxious-insect repellent which contains 0.1-90% by weight, based onthe total weight, of at least one of 2-(1-hydroxyalkyl)-cycloalkanonesrepresented by the following general structural formula (11):

wherein n is an integer of 3-10; R¹ is hydrogen or a straight-chainsaturated hydrocarbon radical having 1-6 carbon atoms; R² is hydrogen ora methyl group; R_(m)′ is m′ of the same or different, straight chain orbranched, saturated or unsaturated, hydrocarbon radicals R which, as asubstituent group, can be bonded to carbocyclic atoms; m′ is an integerof 0-8, provided that m′ should be at least 2 when n is at least 4 andboth R¹ and R² are alkyl groups; the sum of the carbon atoms of R_(m)′does not exceed 12; and when n is 4, R may be an isopropylidene groupwhich intramolecularly bridges between the third and sixth carbocyclicatoms, with the proviso that the 2-(1-hydroxyalkyl)-cycloalkanones arenot


2. The noxious-insect repellent of claim 1, wherein the2-(1-hydroxyalkyl)-cycloalkanones are2-(1-hydroxyisopropyl)-cycloalkanone derivatives represented by thefollowing structural formula (12):

wherein n′ is an integer of 3 or 4; when n′ is 3, m′ is at least 1; andwhen n′ is 4, m′ is at least
 2. 3. The noxious-insect repellent of claim1, wherein said 2-(1-hydroxyalkyl)-cycloalkanones are represented by thefollowing structural formula (15):


4. The noxious insect repellent of claim 1, wherein said2-(1-hydroxyalkyl)-cycloalkanones are 2-(hydroxymethyl)-cycloalkanonesrepresented by the following structural formula (16):


5. The noxious-insect repellent of claim 1, wherein said2-(1-hydroxyalkyl)-cycloalkanones are represented by the followingstructural formulae (13) and (18)

wherein R⁵ and R⁶ are independently hydrogen or a lower alkyl grouphaving at most 3 carbon atoms and the sum of the carbon atoms of R⁵ andR⁶ is 0-3.
 6. The noxious-insect repellent of claim 5, wherein the2-(1-hydroxyalkyl)-cycloalkanone has the formula (13)


7. The noxious insect repellent of claim 5, wherein the2-(1-hydroxyalkyl)-cycloalkanone has the formula (18)


8. The noxious insect repellent of claim 1, wherein said2-(1-hydroxyalkyl)-cycloalkanone is contained in an amount of 3-20% byweight, based on the total weight.
 9. A method of repelling noxiousinsects comprising the steps of exposing said noxious insects to acomposition containing 0.1-90% by weight, based on the total weight, ofat least one of 2-(1-hydroxyalkyl)-cycloalkanones represented by thefollowing general structural formula (11):

wherein n is an integer of 3-10; R¹ is hydrogen or a straight-chainsaturated hydrocarbon radical having 1-6 carbon atoms; R² is hydrogen ora methyl group; R_(m)′ is m′ of the same or different, straight chain orbranched, saturated or unsaturated, hydrocarbon radicals R which, as asubstituent group, can be bonded to carbocyclic atoms; m′ is an integerof 0-8, provided that m′ should be at least 2 when n is at least 4 andboth R¹ and R² are alkyl groups; the sum of the carbon atoms of R_(m)′does not exceed 12; and when n is 4, R may be an isopropylidene groupwhich intramolecularly bridges between the third and sixth carbocyclicatoms.
 10. The method of claim 9, wherein the2-(1-hydroxyalkyl)-cycloalkanones are2-(1-hydroxyisopropyl)-cycloalkanone derivatives represented by thefollowing structural formula (12):

wherein n′ is an integer of 3 or 4; when n′ is 3, m′ is at least 1; andwhen n′ is 4, m′ is at least
 2. 11. The method of claim 9, wherein said2-(1-hydroxyalkyl)-cycloalkanones are represented by the followingstructural formula (15):


12. The method of claim 9, wherein said2-(1-hydroxyalkyl)-cycloalkanones are 2-(hydroxymethyl)-cycloalkanonesrepresented by the following structural formula (16):


13. The method of claim 9, wherein said2-(1-hydroxyalkyl)-cycloalkanones are represented by the followingformulae (13), (17) and (18)

wherein R⁵ and R⁶ are independently hydrogen or a lower alkyl grouphaving at most 3 carbon atoms and the sum of the carbon atoms of R⁵ andR⁶ is 0-3.
 14. The method of claim 13, wherein the2-(1-hydroxyalkyl)-cycloalkanones are represented by at least one of thefollowing formulae (17) and (18)


15. The method of claim 14, wherein the 2-(1-hydroxyalkyl)-cycloalkanonehas the formula (17)


16. The method of claim 14, wherein the 2-(1-hydroxyalkyl)-cycloalkanonehas the formula (18)


17. The method of claim 9, wherein the 2-(1-hydroxyalkyl)-cycloalkanonehas the formula (13)


18. The method of claim 9, wherein said 2-(1-hydroxyalkyl)-cycloalkanoneis contained in an amount of 3-20% by weight.
 19. The method of claim 9,wherein said noxious insects are selected from the group consisting ofmosquitoes, black flies, ticks, millipedes, army worms and slugs. 20.The method of claim 9, wherein the composition is applied to a human oran animal.
 21. The method of claim 9, wherein the composition is appliedto a substrate.
 22. The method of claim 9, wherein the noxious insectsare mosquitoes.
 23. The method of claim 22, wherein the mosquitoes aretiger mosquitoes.
 24. The method of claim 21, wherein the substrate isselected from the group consisting of a sheet, a film and a net.